All fitted now and did it without disconnecting battery, no faults thrown up thankfully, as for the driving experience, can't say anything negative at all, really has transformed the car, huge amount of torque, quieter engine and no penalty in fuel consumption if driven sensibly, would highly recommend it to anyone considering a remap as a viable alternative.
I have informed my insurance company and it added a premium of 45 pounds for the remaining 11 months, so not to bad for 50 bhp extra!!
If anyone needs any info on fitting or a copy of the installation instructions let me know as I found next to nothing on the Internet, also have a write up and review of the brabus d3-s fitted to a s204