While a 15-inch MacBook laptop from Apple is really about the same size and weight as a 15-inch laptop from any other PC maker, Targus strikes a clever marketing note by specifically advertising its Radius Convertible Backpack as designed for 13-inch and 15-inch MacBooks. The $99 case is, of course, suitable for any 15-inch or smaller laptop, and if you don't like the backpack look, the twin straps tuck away into a zippered pocket, and you can snap on a traditional shoulder strap to carry it as a vertical messenger.
The Radius Convertible Backpack is black with dark olive-colored accents, giving it a sophisticated urban look, without being too business-like. We much prefer it set up as a saddlebag-style vertical messenger bag than a backpack, because unless you're walking through a college campus, no one looks good lugging a backpack around.
Even though the case only measures 13.3 inches by 19 inches by 4.5 inches, there's a surprising amount of space inside, even if it's divided up into too many individual sections. The main compartment has a padded slot for your laptop--15-inch models are a tight fit and smaller laptops will swim around a bit. The front half of the main compartment accordions out a bit, giving you welcome flexibility for carrying larger accessories.
A second zippered compartment is narrower and seems perfect for papers and magazines, but we'd almost prefer to see it combined with the main area for a larger storage space. Under the flap, a smaller zippered section has labeled pockets for your Apple accessories--an iPod, Apple mouse, and MacBook power supply--but anything roughly the same size and shape will fit in there. That compartment even has its own zippered mesh pocket on its face, while the front flap also has a small zippered pocket built into its outer face, making it the only pocket (except for a water bottle holder and a Velcro accessory pocket on either side of the case) accessible while the flap is closed.
We appreciate the flexibility of the convertible design, but see this as a much better vertical messenger bag than a backpack. The messenger bag shoulder strap has a thick comfortable pad, although it's missing the built-in cord winder (basically a little plastic hook to wind your excess headphone cable around) found on one of the backpack straps.