Full turbo back Milltek decat exhaust system, panel filter in the box, EGR delete, PD150 turbo and a good front mount will see over 200bhp with a custom remap, it's then just a case of how long your clutch lasts.
To be fair, if you drive it properly ie no loading it up at low speeds in the wrong gear a d bringing the torque on string you'll be ok...bought mine just over a year ago, lad said it had clutch judder, it's actually the dual mass shaking under load, but only ever had it happen once since I've had it coz I use the gearbox properly!!
The TDI's are definately the best of both worlds and I wouldn't have anything else