Not stayed there, but ski'ed with some that did. They said it was basic, but OK. Not really in the centre though. AS PP says, Morg,Pamp,Perilik more central.
If your after cheap hotels (i assume so, cause of Hotel Bor), try the Hotel Rohzen. Its 2 star,basic but ok and in a good location. I stayed there this year.
kevin
try the Elina it is a bit out from the centre (perelik) but the hotel is tsimply the best. All staff go out of their way to help you. Stayed there with our 3 children. taxi into the centre is only a few lev and no problem waiting for a bus as there is one specially for the hotel.
Myself, hubby and 2 daughters have just stayed in the Bor (7th-14th feb) I wouldn't recommend it, it is very basic and the food is very repetitive. Its a 5-10 minute walk uphill to the resort. As the others said, try the Mourgavets or Perelik, we had a look round them and they are alot better than the Bor.