The Good: The Traeger Timberline 850 pellet grill smokes food slowly and gets hot enough to sear quickly. Food it cooks is exceptionally juicy and flavorful. It comes with a meat probe thermometer, links to Wi-Fi and you can control it through its mobile app. The app has a wide selection of recipes that the grill can cook automatically. The Bad: It\u2019s expensive and uses special wood pellets made only by Traeger. You have to clean it often, otherwise it won\u2019t ignite properly. You need to tend it periodically or risk the grill\u2019s fire to fizzle out unexpectedly. The Bottom Line: If you\u2019re patient and have money to burn, the Traeger Timberline 850 pellet smoker delivers outstanding barbecue, but cheaper propane grills are far more practical. A high-performance smoker with wide temperature range, the $1,700 Timberline 850 (\u00a31,849, $3,299 AUD) can roast low and slow, sear at high heat and everything in between. Food prepared by this wood-burning pellet cooker packs complex, smoky flavor that's downright irresistible. Of course the Timberline is double the price of what you'd pay for even premium propane grills. It's also more temperamental than gas cookers, which are far easier to start and keep lit.Both the $850 Weber Genesis II E-310 and $800 Char-Broil SmartChef Tru-Infrared, for example, are compelling yet practical smart grill alternatives. These grills connect to mobile apps to help you keep tabs on what you cook. The Timberline, however, outdoes them in the smarts department and provides complete control over the machine through your phone. It also puts over a thousand tested recipe programs at your fingertips. All that makes the Timberline 850 perfect for dedicated barbecue fans willing to spend this much on a smoker.A smoker, not a lookerAt first glance the Traeger Timberline 850 grill doesn't look that impressive. Compact, boxy and constructed from matte black steel, it's neither sleek nor shiny. The Timberline's rounded lid and stubby cylindrical body give it a distinctly mailbox-like profile. Underneath the grill are two pairs of legs splayed outward to support the grill's 213-pound weight. Thankfully all four legs are fitted with wheels which make moving the grill around less of a hassle.A small metal side table sits to the left of the lid with three handy hooks to hang your tools. On the Timberline's front lip, just below the lid, is a narrow shelf to place extra cooking items. Fixed to the right side is its pellet hopper, a rectangular box that both stores and feeds wood pellets into the fire pot. It has a maximum capacity of 24 pounds, enough to keep the fire burning for at least 8 hours. Traeger says you can expect to burn about 3 pounds of pellets per hour when cooking at high temperatures (400 to 500 degrees F). Smoking low and slow (160 to 200 degrees F) requires less fuel, consuming approximately 1 pound of pellets an hour. The face of the hopper houses the Timberline's control panel. On it you'll find various critical controls including a circular "standby button" and LCD screen flanked by a "selector dial." The panel has a jack to attach the Timberline's meat probe thermometer, vital to knowing when your meat is fully cooked.How this pellet grill worksImagine if a campfire was wrapped in a metal shell, mechanized, electrically powered, and functioned automatically. Essentially you'd have the Timberline 850. The first step to starting this sophisticated smoker is to choose your target temperature. You have a wide range at your disposal beginning with a low of 165 degrees (F) and a maximum of 500 degrees (F) at the high end.After you hit the "ignite" button, an auger switches on. The corkscrew-shaped auger spins to push wood pellets from the hopper into the Timberline's fire pot at a steady rate. There, an electrical heating element, or as Traeger calls it, a "hotrod," ignites the pellets as they enter the fire pot. A blower fan also kicks in periodically to stoke the flames. An internal thermostat works in concert with all these components to regulate pellet burn and keep temperatures under the hood on target.Two steel heat shields, topped by a flat drip tray, sit above the fire pot. They deflect and spread heat energy across the entire cooking chamber. Additionally, the fan circulates hot air and wood smoke inside the Timberline's belly. This enables the grill to cook food indirectly, no matter which of its three grates you decide to use (top, middle, bottom). That's great news to serious backyard pitmasters. Indirect heat is a must for cooking low and slow, the definition of barbecue.The Timberline's design also qualifies it as a true wood-burning convection oven as opposed to a standard propane gas grill. Heck, it even has a "supersmoke" button you press to kick smoke production into overdrive. Gas grills like the Weber Genesis II E-310 and Char-Broil SmartChef rely on propane burners that emit much less radiant energy and apply heat directly to food on grates above. Both appliances try to increase their radiant heat output by placing steel between burners and cooking grates. Weber calls them "Flavorizer Bars," angled metal sections which protect burners from dripping grease. Char-Broil's grill has a large, flat, perforated steel plate that covers the entire cooking surface. Referred to as an "IR Emitter," the plate captures direct heat from gas burners below it then radiates the energy back to grates above. Still, neither appliance is capable of creating flavorful smoke on its own. For that to have to add your own wood to their fires. These machines aren't set up to cook indirectly out of the box either, though you can coax them to do so with a little effort. Total wireless controlTraeger equipped the Timberline 850 with its "WiFIRE" wireless technology, essentially a Wi-Fi adapter and software that allows the grill to connect to home Wi-Fi networks. With it you can monitor the grill through Traeger's mobile app (iOS and Android) right on your smartphone or tablet. Other grill makers have started to integrate similar capabilities into their products. For example the $850 Weber Genesis II E-310 and Char-Broil $800 SmartChef Tru-Infrared both let you see meat probe temperatures remotely. The SmartChef also sends alerts if burners extinguish unexpectedly. You can set the SmartChef's preheat temperature via Char-Broil's app and control the grill's burners once they've been lit.Traeger's solution, though, goes much further. Through your phone, you have total remote control over the machine. You can wake the grill up from standby mode and start its ignition process without being physically present. The app communicates when the Timberline has completed igniting and has preheated to your target temperature. From there you're ready to start cooking. The Traeger app itself is beautifully designed as well. It has a splashy layout complete with lots of mouthwatering photos. What I like most though is the app's large library of tested recipes. I haven't taken the time to count them all but Traeger says there are currently 1,067 recipes within the application. They're subdivided into multiple categories such as "beef," "pork," "lamb" and "poultry" just to name a few. You can even send recipes over to the grill which it will use as programs to cook automatically. To do this simply tap the button labelled, "cook now" placed on each recipe within the app.This Traeger really cooksThanks to its built-in thermostat, the Traeger Timberline 850 demonstrated tight control over temperatures inside its grill cavity. This is especially important during long barbecue cooks when you need to roast meat with low heat and at precise temperatures over many hours. I did have to learn this smoker's quirks before I could use it reliably. Initially, I placed the Timberline on a patio that was partially covered by a wooden deck above. There the grill often failed to start properly unless I left its lid open during ignition. Traeger says its older models had this problem by that shouldn't be the case with the Timberline. Sure enough, I fixed the issue by moving the grill to another section of the patio. Apparently an open view of the sky overhead and increased airflow was what did the trick. I also noticed that the grill won't light properly when its firepot is dirty. If I didn't clean out the Timberline's fire pot between cooks its fire would fail and temperatures crash. Unsurprisingly, ash buildup stifles grill ignition. Improper ignition can also fill the fire pot with unused pellets. Too much fuel causes the grill to overfire, create a dangerous heat spike, and ultimately a mandatory shutdown.