I visited Mount Abu in Jan 2009 and stayed in Kesar Bhawan palace. To start with they gave me a good discount and then an awesome room with a view to remember for life. It has wonderful heritage furniture and very good decor.
The service was a little slow but they were also apologetic about it as there was good crowd build up in the hotel. I had taken a duplex suite, which was very spacious. On the price front, I think other heritage hotels in Mount Abu are much much more expensive then this one.
The location of the hotel was also pretty comfortable, just about 5-10 mins from market and Nakki Lake. The maintenance of the hotel was just perfect. They also use solar energy in the hotel.
Keasr Bhawan did make my stay in Mount Lake a real memorable one. Sure to visit them again if poss.