I just got a Blackburn 2'FER last week. Seems pretty good for $25. I just grabbed it because it was cheap, bright and I hadn't had time yet to research lights (I just began riding again recently after a 30-year break). No regrets.

It's plenty bright enough for a rear light. Adequate as a front warning light, but not quite bright enough to actually be useful to illuminate the road (I've ridden at night only once with the 2'FER as a front light). Choice of steady or sorta-random flashing, white or red. Easy to operate. USB rechargeable. Seems to last as long per charge as the specs (1.5 hours steady/5 hours flashing). I was caught out after dark for nearly 3 hours after missing the last bus home, and the 2'FER was still going.

I'm going to add a brighter headlight but the 2'FER is a keeper for a rear light or all purpose pocket light, including for pedestrians.

Pros:
*Versatile. One doodad for front or rear use. Decent all purpose utility flashlight for a keychain or lapel wear too.
*Plenty bright enough as a rear red light, steady or flashing.
*Adequately bright as a front white warning light, steady or flashing.
*Reasonably visible from sides as well.
*Run-time per charge seems good (may decrease with age and use).
*Recharges in a reasonable time via USB port.
*Detachable rubber "wrist" strap fits easily and snugly around handlebar, Mirrycle mirror post, but not quite around the stem.
*Plastic clip snaps snugly into Bontrager rear rack, with some wiggling.
*Very small, lightweight, well made with positive operating switch. About the size and weight of a plastic digital wristwatch.
*Seems solid and weather-resistant.
*Very easy to operate, including the four modes (white, red, steady, flashing).
*Defaults to last mode selected when turned on again.
*Built-in estimator lamps for remaining charge (green, orange, red for full to low warning).

Cons:
*Not quite bright enough to be useful as a full time headlight for road illumination.
*I'm doubtful about long term durability of the rubber "wrist" strap, but it's easily replaced with Velcro or whatever you like.
*Plastic clip seems highly stressed for attaching/detaching to/from rubber strap. If it breaks I suppose Velcro tape could be used.
*USB micro recharger only, no replaceable battery backup.
*No built in angle adjustment, if you'd rather not blind oncoming drivers. But it's probably not quite bright enough to worry about either.