I think i'm the same boat also, the ride is so harsh now. Whenever I hit a small bump it feels like it when over a deep pothole, but on flat roads its very smooth, mines is a 08' with 81k nyc miles.

 

You do not need to realign car as this changes nothing to do with suspension other than support. BMW recommends this because they want your $ but I've done these swaps many times and you don't need to do alignment.