I ordered three of these a long time ago - I'm pretty sure I've had them over a year now. I gave two away and ordered three more - two as gifts and one more for a backup. With the two I've retained, I've only had accidental activation once or twice, while they've held up well to repeat usage. I don't leave them charging overnight, so I haven't had any concerns with overcharge, as they charge at my desk at work.
For utility they are fantastic. There have been several times where my main EDC flash (the brass Massdrop/Lumintop flashlight often seen) has been left at home, and with one of these on the keychain, I'm never without light when I need it. Sufficiently bright on high, just a tad too bright on low (for theater navigation), overall I'd say my experience with these has been solid. The only TUBE no longer in service was in a friend's +20 MPH cycling crash. It still worked, but the rubber button was sheared off, along with a portion of his jersey pocket.
Heed the words of warning from those who've experienced issues, but know these aren't causing everyone trouble.