I’ve been a couple of times, once with the Missus and once for a stag, and I’m going to go against the grain and say it’s OK.
The Old Town, seeing the clock, walking across the Charles Bridge and the castle are great, however, it is overpriced (which is to be expected I suppose) in the centre and for an ‘Old Town’ I was a little disappointed walking past Marks and Spencer’s, Starbucks etc.
It’s definitely worth doing once but I do feel it has been built up a little too much and, in my opinion, wasn’t as great as people had built it up to be.
We found a couple of great underground bars but if I went back I’d certainly do my research on other areas of Prague rather than just the old town.