+1 on starting with BM3 stage 1, makes a huge difference, go from there. Just know that all the stage 2 stuff is going to raise the power higher in the rpm band; driving around town it will feel doggy because of turbo lag. Will be a beast after 4k rpm though, just depends on what you want and where you drive. I love the instant throttle response of the Stg 1 setup. Here's a vid of a quick pull I did with my 15 428i right after I mapped the BM3 STG 1 tune on.