The MSP was a great chassis with a terrible engine. The FSDE was never designed to be turbocharged, and the mazdaspeed cars just had a factory installed callaway bolt-on turbo kit. The stock rods are done at 200hp, the head sucks, stock tuning has giant peaks and valleys, I could go on...
The new VW 2.0t is an awesome motor. 200hp stock, 80 more HP is just a flash away. Give the DSG trans a chance, but drive it in manual mode. The auto program is awful. Don't get a model (Passat, base Jetta) without paddle shifters. I good downpipe and intake helps with the power drop at 5k rpm.