That's a nice sized and all around good machine, it should have a cummins engine in it and with a six way on it, makes for a very handy machine to use and have around, as for hp it should be in that 115-120 range and be in the upper 20,000 lb range.
As for opinions, I like that case dozer myself, they were easy and fun to run, got something done and for farm work were about ideal depending on what you want to do.
You never said if it was a low ground pressure dozer or standard track pads under it or what your wanting to do with it per say, but as for that model of dozer if it is in good shape and the price is right, I'd say buy it and use it.