Murgavets is in the middle of the resort. Great hotel stayed 5 times nice clean warm rooms. The bus goes from outside the hotel 10 mins to ski lift. Bit of a long walk!! Hotel Pamporovo is a bit closer to the lifts but out of resort so if you want the nightlife you have a short taxi ride into resort centre. Both good hotels I would stay at the Murgavets though.
Not stayed at the Pamporovo Hotel but been to Pamps a few times now, and reports of that hotel have not always been favourable. Mourgavets is very nice hotel if you like them big and modern. Stayed there last year, and have no major complaints. Everyone will warn you that it faces the Red Lion pub, which plays music til 3-4am, but after a day on the slopes, and then a night on the town, you probably won't notice. I certainly didn't lose any sleep because of it, and I am a light sleeper