I got one of these $15 CREE magicshine clones from Amazon when there were closer to $18. I already had a light I was happy with, but had to see what it is about. One day I will do a review of it vs my more expensive integrated battery lights, but for now I can only offer an initial impression.

I don't use the CREE MS clone on my bike, I still use my other light. The MS clone is plenty bright, but not near 1200 lumens, maybe more like 800, but that is fine, my main light is 700 lumen and just fine for me most the time. The main things I didn't like were:
1) External battery meant one more thing to mount, extra wire, etc. And the included battery pouch is pretty cheap.
2) External charger vs USB means I need a charger anywhere I want to charge it. (work, home, on vacation, etc). USB is just so simple for me
3) Optics are not great - simple beam pattern vs a company like L&M which has done R&D on beam pattern and focuses more light on the road instead of in commuting peoples eyes.

Many people rave about he wide angle lens you can buy for it. I got one but haven't tried it yet. I plan to try it and probably use this light on my round town beater bike.

I have used the light a few times as a headlamp while going in my crawl space...worked great for that I guess.

Overall at that price you can't go wrong I guess, but if your priority is quality over price you may be happier with one of the really great lights on the market as your everyday light.