I was there tonight, for the first time:
1) The best sirloin I've ever had. (Definitely NOT the best STEAK I've ever had, though; that title easily goes to Luger's. Also, I think Angelo & Maxie's sirloin is just as tasty, but it's a much thinner-- and less expensive-- cut, so I give the sirloin edge to Spark's.)
2) The tossed salad was bland.
3) The steamed asparagus was crisp.
4) The creamed spinach was decent.
5) The mushroom caps were GREAT-- definitely the best of the side dishes.
6) Unlike some of the horror stories I've read here about the wait, we were taken exactly on time. (We had a 7PM reservation).
7) Our waiter was extremely friendly.
8) The place is VERY noisy.
9) As "advertised," the wine list was extensive and the mark-ups were quite reasonable.
My rather cliched and unremarkable conclusion: this was the best steak place I've been to in Manhattan, but if I had the time, I'd definitely rather go to Luger's.