1.8t = power and more mods for cheap, you can easily make 200+whp/250+lbs w/ bolt ons

TDI = fuel economy for the win, not much for whp but you can make hella lbs... from what i've been told its pretty easy to get around 150whp/300lbs somewhere around that range

i will tell you both cars have very strong motors, stock block on a 1.8t will hold 300-325whp, oem parts on these cars are very strong, i have the most powerful k03 around here and only issue i've had is MAF sensors... you will learn german cars are bad on sensors/wiring,etc.

but personally it all preference... if i was going to buy one right now i would buy either a 2.0t or a tdi 1.8t would be my 3rd choice