So here is my summary as of date of all the things I have read (I still have on stock).
OSS
It cost $525 + tax. It seems that people say that this is the true way to go since there isn't any problems with them (is it because not a lot of people have them due to the price to really say there are issues with them?). But the process is unique, you send in your headlights and they install the OSS and send you back your headlights OR if you have very new headlights, take some pictures of them and send it to them to qualify for a trade. You need to put down a security deposit, they send you the OSS head lights, and you send back your stock as a trade, etc.
PG Thunders
It cost $20. It's just a bulb replacement. You get white light instead of yellow. People do say that these bulbs dim. A lot of people that go these are unsatisfied with the brightness. Some like it because they didn't want to do too much to the car and go through all problems with other units.
Lux
I don't know much about these except people loved them and they got recalled. Now, its uncertain whether they are fixed? And if they work on 2011. Cost ?? From my point of view of the pictures I have seen, they look very similar to AiB (maybe brighter?).
AiB
It cost $299 + tax. I've read a lot on the forum that people have issues with these. I was told the V3 of AiB doesn't have any more issues?? Though if there are issues, eas has been on top of it to help fix/replace any bad units for their customers (it just suck for people that doesn't live close to socal since you'll be waiting in the mail for them). Eas also do free local installs for forum members. Some people are unsatisfied with its brightness. Though in pictures, they look uniformly aligned for perfect light distribution (between inner to outer rings).
HID
It cost $170 (shipped). There are no cutting, drilling, damages, etc. to your M3 (there are DIY videos that does cut a piece of the headlight, but that's not for the M3). Alex @ Alpine does free installs (if you're close by he'll come out to your work and install them for you??). These are very bright. Of all the people that got them, I haven't heard any that complained or want to return theirs. Some say from looking at the pictures that the inner ring bleeds to the outer ring and that they might get hot.
I started off wanting OSS but they're not local and it's a bit expensive. Then I wanted AiB since they look great from the pictures. But then price and I'll hate to be troubled with issues if there are going to be issues (eas not open on the weekend
). Then HID, then back to AiB and now back to HID.
