I have been looking for a tidy Mk1 GTI for a few months now and found a very nice Mars red example from 1981 with only 90K on the clock, professionally restored with a (very) full service history and photos. So I went to see it this morning and was really impressed when I saw it on the drive: immaculate bodywork, glistening in the sun, lovely old-fashioned burble from the engine on start-up, very clean unmodified interior, stock steel wheels, etc. Perfect! 
I let the owner drive the first couple of miles as I sat in the passenger seat. What struck me first was how narrow the whole car felt. There was also a fair bit of squeaking, rattling and banging coming from more or less everywhere and the seats felt a bit flimsy. All in all, though, it was pure nostalgia, like being a student again!
Then we swapped over and I took the wheel. As the engine was now nice and warm, the owner encouraged me to give it some beans and I duly obliged. Holy crap, it was... crap
Maybe there was a problem with this particular engine (although I don't think so, seeing how meticulous the owner was), maybe I have become too used to my Mk6's 275hp (but my daily drives are a Ford Transit van and a Renault Espace, both diesels), but it was one of the most disappointing drives I have had in a long while. It felt more like driving my son's 60hp Citroën C2. What an effing let-down 
At the risk of upsetting Mk1 owners (which is why I'm posting this in the Mk6 section), there is absolutely no comparison whatsoever between the first and the sixth generations of GTI. I had been looking forward to driving one SOOOO much and, yes they are very pretty little cars, but this one was uncomfortable, noisy and gutless. The steering was really heavy and the brakes were rubbish, despite having been upgraded with big perforated and vented discs. The engine just wouldn't rev, it took an age to get past 4000rpm.
I am so disappointed

The Mk1 GTI: gorgeous, but rubbish 
Theres something wrong with it.
Im guessing by the age it was a 1600 (was it 4 or 5 speed?) so not a big amount of torque and they need reving.
The throttle responce should be instant unlike the slow modern electronics of modern cars. It should rev quite quickly.
Modern cars have WAY over servoed brakes for the weeklings who have bandy legs who cannot press pedals. (if the rear brakes are setup correctly the brakes work fine(very few are!))
Yes there not fast by modern standard 8.2 to 60 or 9.5 for the 1.6.
Rattles mine does not rattles. Our mk5 i have had to cure
far more rattles in a couple of years than i have with the mk1 in near 20!
Ride mines very smooth (but leans abit) the mk5/mk6 is like riding with no suspension in comparison. (guess this one has uprated suspension they cause the car to shake to bits and will cause the rattles)
Steering heavy, of cause it is, its not power assisted people had muscles back then and did not expect everything done for them. The steering feel on the move though is far superior to the mk5/6
Narrow inside yes but compare boot and rear seat space not much more or progress for a car thats 20 inch longer with the mk6. Its also far narrow on the outside.(far better packaged than modern cars) You should see how little space the mk1 takes in my garage compared to the space i have had to make for the mk6!
Seats flimsy mine arn't if anything they grip as much if not more than the mk5/6 i like them better than the mk5/6 seats.
Sorry but you won't get the shove you get in a turbo diesel that make you think there quick they don't have the torque or the on/off boost shove.
You need to watch the speedo and try an 1800 and do some timed 30-70 30-50 50-70 runs to see how its not that slow.
0-60 8.1sec, 0-100 24.1sec, 50-70(5th) 8.4secs. and 38mpg+ To also compare it to a car that prob does 0-60 5.6sec and quick low in gear times as well (based off scirocco R figures) is just crazy. Afterall a standard mk6 GTI is as quick as a standard escort/sierra cosworth was back in the day!
Sorry but speed is not everything light weight,nimble, feedback its what Colin Chapman preached.
two videos on a mk1 test drive to bore people
http://www.youtube.com/watch?v=1hwEo4JLY60http://www.youtube.com/watch?v=z-r-oyO3fVE