Very quiet, though there is some marvellous museums and the like, one of the local tavernas does stay open till about 11pm.
The library has a good selection of english language literature.
If you want discos etc youd be better off in Borovets.
Well, if its nightlife you want, then go to Pamps, the famous Daks (where they the barstaff just won't let you leave before 1pm!) and BJs to name just two of its bars open until stupid o'clock. Hope I get a new liver for Christmas!