I was messing around on youtube earlier and came across an E46 Technique Tuning stage 1 turbo video. The TT turbo seems to be the benchmark on the E46 forums, so I decided to see how it compares to my Z4 with full exhaust and modified gearing. It looks to be close from 30 mph - 85 mph, with the TT turbo maybe a tick faster. I would put my money on the Z4 off the line due to the lighter weight and my LTW flywheel combo. The E46 appears to have stock gearing, so it will have a better top speed and get better gas mileage. It's pretty interesting to see the two very different ways of making power - non-intercooled centrifugal supercharger and swapped final drive versus an intercooled turbo running more boost.
http://youtubedoubler.com/dyAX