Each function pops up with a click of the top button. The display is also touch-sensitive, and with a finger-swipe you can dig back to previous days' readings. The Pulse stores the last 10 days of data.
Syncing with Android or iOS is as simple as pressing and holding the top button for three seconds, or waiting for the Pulse to sync automatically via the Withings Health Mate app. The Pulse O2 also works with a wide variety of phones: iOS 5 on an iPhone, iPad, or third-gen iPod Touch or later; or Android 2.3.3 on a phone or tablet, is all you need -- which includes some iPhones and Android phones that don't always work with other recent Bluetooth fitness trackers.
The Pulse can also be worn as a simple clip-on device: for $119, you get the Pulse plus a wristband and a rubber clip accessory. In clip mode, it's actually easier to use.
Heart rate readings seemed accurate compared to gym equipment I tested against. The data is collected and graphed in the Withings app, but no extra coaching is offered on the device itself. There is, however, in-app coaching, similar to what Jawbone offers, but more along the lines of health suggestions based on your data.
Sleep tracking needs to be started before going to sleep, but turns off automatically: waking up and taking ten steps will shut it off. I like checking how much I'm sleeping, but the Pulse makes you click through three menus and then touch a display to either a heart or moon-shaped icon to start heart rate measurement or sleep tracking. It's too many clicks and swipes and touches, and isn't intuitive.
One more important note: the Pulse isn't water-resistant. A Micro-USB charge port pops out the side, which at least avoids the need for a dongle, but also means you can't get the tracker wet. Other bands can be worn in heavy rain or in a shower.
Withings claims two weeks of Pulse use on a single charge. A full charge of the Pulse got me about 10 days of use with the older model. I've only been using the current one for a few days so far.
Health Mate app: Lots of health options
Withings has a nice ecosystem in its Health Mate app, and a new redesign offers a cleaner timeline for collected data, more like what the Jawbone Up offers. There's an attempt at social competition, too, with new fitness goal challenges, but the app doesn't connect to Facebook and makes you email an invitation or scan for local devices via Bluetooth. The newest version of Health Mate also allows iPhone 5s users to tap into the M7 chip and use their phone as a pedometer if they don't have their Pulse (or, if you don't own a Pulse at all and want to use the Withings app). I tested the Pulse O2 on an iPhone 5s.
The Health Mate app also has new reminders for various health-encouraging habits: sleep more, or drink more water, or take your blood pressure. The app can ping you with these reminders, and they're generated based on what the data you're sending to the app. In the few days I used the Pulse O2, I couldn't get a strong sense of the coaching, but I'll update this in a week or so.
Withings has a wireless scale and blood pressure monitor that sync with the app, and combine to form a more detailed health-profiling ecosystem. You can also link a BodyMedia armband, if you have one. The app links with RunKeeper, Runtastic and MyFitnessPal, too.
Conclusion: A new band on an old tracker
Credit goes to Withings for allowing current Pulse owners to get some new ways to use their tracker, but the Pulse O2 as a wearable fitness band lacks the type of display I'd like to make this easy to use when working out.
Still, the added features and the affordability of the whole package make the Pulse one of the more attractive fitness bands-as-watches out there, especially now that the Fitbit Force isn't on the market and the FuelBand's future is in question. It works in tandem with a variety of useful Withings health hardware accessories, too. The Pulse O2 isn't a fitness band of the future. It is, however, a very welcome upgrade for the present.