Great hotel - location, staff, price!
My boyfriend and I just got back from a long weekend trip to NYC for a wedding at the Waldorf Astoria and we stayed at the Affinia 50 from Thursday through Sunday. I used to live in NYC and my boyfriend is a complete travel snob (he's more of a Four Season's type) - and we both really enjoyed our stay at the Affinia 50. 
The location was GREAT, the staff was very helpful and nice (we even got an upgraded room with a balcony), the room was nice and clean (the bed was so comfortable!), and the price was great for this time of year and the location. Our balcony faced the east side and the view up/down 3rd was nice.
Yes, I had read about the elevators (they are slow, but it was never a problem or a ridiculously long wait), there is street noise (we were on the 18th floor) but that's NYC and it didn't bother either of us - they do supply each room with earplugs, but we didn't need them, and the bathrooms were small - but its NYC, what do you expect? Our room was a little too warm and the heater wasn't adjustable - but we forgot to ask the staff to fix it and it ended up being ok. We had breakfast out most days and one day tried the "Luncheonette" a couple doors down which was a better value than the one the hotel offers. You can hear people in the hallway and in their rooms - but nothing that was annoying or prying - or rather, neither of us seem to notice. The guestroom we stayed in (#1802) was small, but the two of us seemed to do fine - and that's just NYC. Next time, I think I'd spring for a suite which had a sitting area next to the bedroom so that we can spread out more.
The manager was great, the staff and doormen were delightfully helpful and I just can't say more about the great location. And the added touch of the balcony (thank you Guadalupe Olmos-Galasso) was perfect! 
No, its not the Four Seasons, but we really enjoyed our stay in the city and at the Affinia 50. Our only complaint is that our trip wasn't long enough. We'd definitely stay there again!