I have two of these lights. I've had one mounted to my bike for the past year and a half and wanted to increase visibility at night. I liked the first buy so much, I got a 2nd one. I use them during my commute to and from work. I ride on the road with cars on both low-traffic and high-traffic roads. I wear one on my helmet and the other on my seat post. My main concern in buying this was that it is has a low profile, is easy to recharge, and can be easily carried along if I ever go running. (Note: I've not used it for running yet. However, when but when (if) I do, I plan to strap it to my watch or to a headband.)
The battery life has never been an issue for me; however, I don't usually let them run out. My commute round trip is little over an hour and I go 2 to 3 days before recharging. As for the light modes, I think that they offer an adequate amount of variety w/out being over the top. I typically use the low flash during my morning commutes when there is plenty of light. When I'm riding at night, I use the fast strobe setting to be sure I'm giving approaching cars adequate time to notice me.
I like how I can position the light vertically or horizontally without having to maneuver the mount in some weird way to make things work. I can't comment on how durable the clip is on the mount as I'm pretty gentle with my stuff. I only take the lights off when it's time to charge them. I guess that as long as you're taking care not to bend the plastic parts too far, you'll be fine. Five stars from this guy.