I picked up a 335d a month ago and I LOVE it, sadly it destroyed the experience of driving my Jetta. The emissions systems are a real problem, If you are not planning on deleting I would probably say not worth it. I got my first check engine light 2 weeks in, bad temp sensor in SCR tank, 3k+ to fix because you have to replace the whole tank. I knew what I was getting into so not that big a deal because I'm deleting it. Cbu, emissions, and bad diesel will cost you but if u mod you eliminate most of the risk. All you need is a good tune, have the intake walnut blasted to clean the carbon, and a turbo back exhaust. Power is great stock but after a tune you'll get a nice bump.