I did a 4-night award stay in April. Got a Platinum upgrade to the club floor, which I think improves the room slightly, adding an LCD TV, for instance. You'll have access to the club lounge no matter what, which features a pretty large breakfast spread and a decent happy hour with snacks and drinks.
When I was there, they were still completing lobby renovations, but honestly I didn't find it bothersome at all - there's really no noise, and the construction area is completely blocked off from the temporary check-in. Other than that, it was very nice for a Sheraton, okay location about a 30 minute walk from Red Square, definitely a good value for the 6k points/night I paid (PER50 at the former Cat 5 level).