What a difference a year makes, yeah? 13 months ago, we were giving Drift Innovation's latest helmet cam (the HD170) a run through the gauntlet, and now, we're giving that unit's proper successor the same treatment. The simply-named Drift HD action camera is largely the same type of device, albeit one that's 25 percent shorter (this one's just four inches long) and offers a replaceable lens. Moreover, there's a waterproof casing that's on the way, though said shell wasn't ready during our testing phase. The company managed to inclu