Jawbone's Up has a bizarre history. The fitness band was the company's fastest-selling product of all time when it hit the market last year, and with good reason — we liked it a lot in our review. Soon after, though, many users reported that after a few days or weeks of use their Up bands simply stopped working. Jawbone acknowledged the problem, offered a full refund to anyone experiencing any problems with their device, and promised to come back stronger next time.

Come back Jawbone has, with a re-launch of the device that company VP Travis Bogard says is free of the problems that plagued Up, and offers a number of new features as well. The $129 device now comes in a number of new colors, which Bogard says were created almost by accident — Jawbone used different colors to differentiate its various prototypes, and liked some of them so much they added them to the final offering. It's also much better made, and rigorously tested: Bogard couldn't stop talking about the 100-plus patents the company has for Up, the testing standards it had to create because military specs weren't comprehensive enough, the "Big Shower 2000" that tested the band's water resistance, and the like.

The Up's problems were two-fold: the original model wasn't perfectly water-resistant, and the trace amounts that penetrated the outer shell were enough to prevent it from charging or turning on. Some people also bent the Up in unexpected ways, either while putting the device on or fiddling with it absentmindedly; that had a tendency to break the circuitry inside the device. Bogard promised those problems are things of the past, and that having a year's worth of consumer feedback was an invaluable resource as the company designed the new version.

Up is designed to work with Jawbone's mobile apps, which have been overhauled as well. The app itself is simpler and easier to use, making it really easy to see your progress for the day, recent trends, and what your friends are up to. There's also more data available to you: you can input workout results, your meals, how you feel at a given time. It's almost like a fitness-based Path, giving you a way to track all your life's activities. This is Up's biggest advantage over Nike's Fuelband — instead of having a single metric that is only useful in comparison to your previous data, Up lets you track much more. Up is also a much better-looking device, something you won't mind wearing on your wrist; Bogard called it "functional jewelry," which is a pretty apt description.

Jawbone's banking on customers being willing to give it a second chance with Up — its no-questions refund on the last model certainly curried good favor with users, and it may have earned another try. Bogard is confident that the company has it right this time, but with the new Up now on sale for $129, we'll find out soon enough whether the second time's really the charm.