Hi Drysdale
I have owned 4 Golf GTIs, 2 Audi 80 Sports, an Audi 80 1.8E and an Audi 90 2.3E. I then had a Golf VR6 for 4 years followed by 4 Audi A3 1.8T Sports.
All have been petrol and manual gearbox. All have been good in their time and I have throughly enjoyed driving each one. I generally do around 20,000 miles a year and have taken each one to Europe for a holiday.
I think the A3 1.8T Sports just had the edge for me, but perhaps because they were the latest models. The 1.8T engine was super.
The thing that changed me to a diesel was the DSG gearbox. The only way I could get the SE spec and the DSG was to go for the 2.0TDI. I have not regretted the decision. It's a little noiser than the pertols but not so much that it spoils the experience. The general feel when driving is very similar to my 1.8Ts but with much better fuel consumption. My journey to Austria this year should cost me a lot less both because of the better mpg and diesel is so much cheaper than petrol in Europe.
If you are considering a 2.0TDI my advice would be to go for it and also to go for the DSG gearbox. You will not regret it. A manual 2.0TDI requires quite a lot of gear changing to keep it going well, but with the DSG it's just a flick of the stick or paddle.