I've just sold an Si that I had for the last two years and 20K miles. Was very reliable and only needed an AFM other than regular service bits. Only depreciated by 60 quid during that time which was good!
Not sure about the good on fuel comments, I never got over 30mpg which is a bit poor for a low powered 1.8 IMO.
Parkers lists the top speed as 122mph and the 0-60 as 9.2secs. It goes ok, but is not exactly what you'd call fast though.
Having said that a looked after low mileage GTi would make a good buy for a cheap and cheerful car.
Dan