HAFH is located at one of the best spots in Nainital and offers a superb view of the city and the lake. It does take a steep climb of about 30-40 meters to reach it and can be tough for the elderly. But if you're ready for the workout, you'll be rewarded with a breathtaking view, cheap acco and the Colonel's warm hospitality. We went during the off-season and there were no other guests - got the best room available (the 1st one). Even the Colonel's staff was on leave and hence food was an issue, but he opened his personal kitchen to us and we fixed our own breakfast.
The colonel has a few cars of his own and can arrange for a sightseeing trip at a modest expense, but we had our own vehicle and didn't need it. He did chalk out an itinerary for our nainital visit though, which was very helpful and sweet of him. The high-altitude zoo is a 10 min walk away from HAFH and a must-visit.
All in all, a good experience - just don't expect Hotel like service. Its a home stay and as long as you keep your expectations in check, you'll have a good time.