mine has done 38k now, and no real problems, other than a couple of vibratory noises!!! but turn the stereo up and its fine!! I love it, have done since day 1 and I love it still!! You will, I am sure, already know that on paper there is quite a lot of difference in performance, but we have one member who has a VTS now, and says its pretty quick - a lot depends on the driver and conditions at the time of course.
at the end of the day get a decent couple of test drives if you can and decide which feels nicer. you will, I expect, get some problems, but you get problems with any car, even Mercedes and BMWs, despite what some people would have you believe - I run the fleet at work and we have a lot of BMWs and Mercs, and they also have problems and cost about 4 times as much as a 172!!!