Sheraton is more business hotel then National. National is all about trying to get Kremlin view room and enjoying hotel where every room is different and understanding that each room furniture is different, since it's 100+ years old restored very nicely. But as a result having to deal with small baths, which was the norm back 100 years ago unless you stay in a new wing and not having a Kremlin view, which makes no sense.

Sheraton is a pure SPG hotel. May be not worth Category 6, but no surprises at all. Everything you need from the hotel is right there, when you are in city on business. Not so cool if you are on vacation, but great for smooth and painless stay. The only concern from some guests are excessive presence of bodyguards in lobby of Russian wealthy people visiting restaurants on premises including Sheraton owners official police escort with machine guns.