I am not familiar with Kenwood, but I used to install Alpine/Pioneer/Eclipse. Both Alpine and Pioneer are pretty good. Alpine's new touch screen is awesome, but I think Pioneer's navigation is more user friendly and has some nice features. Another benefit of Pioneer over Alpine, is that the "safety" feature can be easily bypassed, so you can make adjustments while driving and watch movies while driving (not that I recommend it, but everyone does it). Eclipse's new units are supposed to be the fastest, so check them out too.
Go to a couple stores and play with the units. That is the only way to make a decision of what's best for you.
A forum community dedicated to BMW E46, E90, and F30 owners and enthusiasts. Come join the discussion about M performance, turbo kits, engine swaps, builds, modifications, classifieds, troubleshooting, maintenance, and more!