Just passed through UB a few times during my stay in Mongolia and stayed in 3 guesthouses:
Khongor - fine, good location, offer tours, some helpful staff. Don't think it deserves the status the LP guide gives it, though.
Golden Gobi - I thought this was the best of the bunch in terms of comfort and cleanliness, and again, good location. Dorms and private rooms good value. Also does tours and has pretty helpful staff.
UB Guesthouse - disappointing. The place was ok, through the rooms were a bit rundown and crowded. People who were doing tours with them seemed happy, and the tours got pretty good reports, but I had booked a tour elsewhere and as son as this became known the owners became distinctly unfriendly and unhelpful. I wouldn't advise going there unless you are planning to book a tour through them.
