We stayed at the Ten Hill Place Hotel from 8-10th February 2008. The hotel is pretty central (less than 10 minutes walk to the Royal Mile, 5 minutes walk to the Grassmarket, 15 minutes to Princes Street).
Staying at this hotel was a really nice experience. It was spotless. The rooms were lovely and modern with comfortable beds, a safe, tea and coffee making facilities, complimentary bottles of water, and the all important packets of shortbread. Others have mentioned the glass bathroom door. Its not a big issue but I wasn't a big fan of it.
I know alot of people have mentioned the issue of the small dining room and the waiting at breakfast. I was a bit concerned about this but it wasn't a problem. The staff were very professional and on both mornings were very quick to get us seated at a table, generally in less than 10 minutes. As we weren't in a rush for anything it was completely fine. The breakfast itself is great. It is buffet style and you can get a full cooked breakfast, cereals, meats and cheeses, etc. Even though it was busy for breakfast, the staff continuously replenished the food, so there was no danger of anyone going hungry!
I would definitely recommend staying at this hotel. It is nice and quiet but at the same time you don't feel out of the way of things as everything is a short walk away.
A final word on the staff - they were really helpful and friendly - what more could you ask for?