This is a rather late review; I stayed at Gladstone House with my boyfriend in June 2010 for 5 days.
The house is lovely with very large, clean and well-furnished and decorated rooms that were very comfortable, though the floors creaked a little in spots! There was a large window that let in plenty of light with thick curtains for night. We had booked a double room but got a triple so the room was very spacious with a double bed and a single, large desk, armchairs and a large closet. Plenty of space to move around in, even with our large luggage. Beds were very comfortable, room was quiet and dark and we got a good sleep every night. However, the ensuite bathroom was pretty small - there was very little room for the door to close and if you are somewhat larger in stature it may be very difficult to get in and out. We managed, but neither my boyfriend and I are large at all. The toilet and showers worked perfectly and were spotlessly clean. Towels, soap, some amenities like cotton wool was supplied. The room also had a hot water kettle, complimentary tea/coffee and some biscuits daily. Free wireless too which worked perfectly. Oh, and there was also a large TV where we watched Wimbledon and the World Cup ;)
Breakfast was truly one of the high points - served fresh every morning for an hour, you get a choice of a main item (selected through a menu which you place the day before in a bowl in the hall) which included omelettes, full Scottish breakfasts, pancakes and more. You also get a choice of several items from the sideboard (cereals, fruit, pastries, yogurt etc), a pot of hot tea/coffee and piping hot toast. This was enough to keep us going for the whole morning and even into lunch on days!
Location wise, Gladstone House isn't extremely central as it's about a good 20-30 minute walk to the centre of town/Waverley station. Buses stop just right outside Gladstone House though and are pretty convenient (maybe a 10 minute trip), but if walking is a difficulty I would definitely get a day pass for the bus and would factor in bus fares into cost as they can add up quickly. We had our own keys to the main door and could come and go as we liked (though the lock could be a little dodgy at times).
Tom and Hamish were lovely hosts and very welcoming. It was easy to book our rooms (from across the world in Singapore) through email. Note that there is a surcharge with credit card payment - I usually clear these things up in advance to avoid nasty surprises, but just a heads up. We really appreciated the welcome folder filled with lots of info about places to eat, buses, walking routes and so on and there were a number of travelguides that could be borrowed in the hall. One problem was hoisting the luggage up the stairs - we had one very large and heavy piece of luggage and had to get some help from Tom and Hamish to get it up (luckily only to the second floor). If you have trouble with stairs, this might be a problem.
Overall for the price I would probably go to Gladstone House again though the location was not as central as I would've liked. For those who enjoy a warm homely place to stay, this is an excellent bet, but it might be difficult for those who have difficulty with stairs or too much walking.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC