So got a chance to try out deAutoKey's LED bulbs for F2x, F3x and have to say I am absolutely impressed.
The left side of the tail lights are the OSRAM LED and the right side is the newest CREE LED. Cree is evidently a little bit brighter but Osram have a more amber turn signal light (Cree's amber is a little bit mixed with red maybe due to housing). I'll update with pictures on the built quality but it is very high quality built. Also, brake lights had 3 bulbs and I only ordered 2 on each side so one of the middle bulb is actually oem stock.
Well I'll let the pictures do the talking.
As you can see in this one, the outer bulb is evidently brighter. The middle one is the stock oem. the inner one is LED as well but I think its just angling issue so you can't see it as bright.
In the picture, both turn signal is about the same color but in reality, left (Osram) showed a lot more orange/amber than right (Cree). But you can tell that the right is a little bit brighter.
Update:
http://deautokey.com/product/bmw-f2x...e-turn-signals
Now I have to mention that it did flash on engine start but not any other time. After reading some user on f30 using other led stating led flash when driving, I've decided to test it out further this weekend. Hopefully video will be posted. Meanwhile, if you enter my username, cbbplanet, at checkout, you will receive 10% off the purchase