Yeah, I ride with one on the bars on its own. It’s fine. And the newer one, I think, is about 20% brighter.
On the road it’s perfectly adequate on full beam, though if you have potholed roads that you normally fly down at 30-40mph then you’ll be outrunning the light and having to scrub a bit of speed.
Off-road you can get by – fire roads ought to be fine but again you’ll only be able to go so fast before you start getting some surprises.
Two things to point out: Firstly the zip-tie mounting is impossible to fit tight enough to hold the light steady at a decent speed on rough roads, so I’d recommend the bolt-on metal clamp (which costs extra). And secondly if you go out riding with other people then IME there’s a good chance they’ll have lights that render yours pretty useless.
If you’re in the market for one of these as a bar light then it’s worth waiting to see what the new Lezyne lights bring – they look like they’ll take the fight to the Joystick… cheaper, brighter, USB charging, no word on run time yet.