I just installed a 2003 1.5 vti throttle body onto my 03 dsi. Everything was a direct change over, I just had to re position the tps to lower the idle. I honestly don't think it changed a thing performance wise lol. This is an Australian model, both cars are cable.

 

After a 350km journey today, the car has more low to mid pull, smoother through the gears. However it seems to have lost some torque. Not as good in top gear going up Hills.