I knew 2 other RS6s running West Tuning maps, all seemed to be fine. Car feels ballistic, but it only showed 505 Bhp on last rolling road. Only, hah. 
I imagine I would need to gut zorst precats to get much higher anyway.One thing I don't know is what gearbox mod is done - is it just the plus map or more? I can't help you on that one. In my opinion the value for money would probably go to Grizz or MRC, they do much more work on the S/RS cars after all.
