Good, but not great
Perhaps the best thing about the hotel is the location. A short walk from Grand Central Station so if you're in and around that bit of town, this hotel is well placed. 
We stayed for 4-nights. This'll be the third time we've been to NYC and we've stayed in a range of hotels. Granted, a hotel in NYC is more often a place to sleep rather than a location in itself. We were up on the 19th floor round the back and tho' the view wasn't great it was very quiet during the night and not too busy in the hallway.
The room had a pleasant decor, but the bathroom was bordering on grim: cleaned yes but the ceiling had peeling paint which made the room feel scruffy. Maybe its a european thing - but I like to have have tea/coffee in the room. I also think wi-fi in the room shouldn't be a big deal nowadays: still a wires connection at extortionate rates although you can go down to the lobby to access a free service.
There is a Starbucks in the lobby as well as two restaurants (Chinese/Italian). I don't like Starbucks and we didn't like the look of either restaurant so we went across the street - there's a wide range of alternatives if you feel the same. 
We had a couple of problems with the lights in the room - the staff were great and it was fixed straight away. The gym has plenty of options. 
This Radisson is decent value for money, perhaps if I'd seen 3 rather than 4 stars I'd have been better prepared.