I think I'm higher on him than most. I have him at #12 on my Top 50 pitching prospects list in the 2013 Baseball Prospect Book. That would put him in the 20-25 neighborhood on a unified list (I'm working on one of those for next week). Baseball Prospectus has him in a similar area at 28. Other sources don't have him as high: Baseball America has him at #54 for example, as they are concerned about his curveball not being very impressive.
Here is what I wrote about him in the book. More comments afterward.
Noah Syndergaard, RHP, New York Mets
Bats: L Throws: R HT: 6-5 WT: 200 DOB: August 29, 1992
2011: Grade B-; 2012: Grade B+
Noah Syndergaard is one of my very favorite prospects. A supplemental first round pick in 2010 from high school in Texas, he’s thrived thus far in pro ball, generating very enthusiastic scouting reports to go along with excellent statistics. Syndergaard has a 92-98 MPH sinking fastball that gets on top of hitters quickly. He picks up a lot of grounders (2.16 GO/AO), while maintaining a strong strikeout rate (122/31 K/BB in 104 innings in Low-A, just 81 hits). He’s developed a very good changeup, and I think his curveball is underrated. He commands all three pitches well, shows positive mound presence, and seems like he will be durable. The Blue Jays have managed his workload well. Assuming no injuries or weird command slippages, Syndergaard can develop into a number two starter. I really like him. He was traded to the Mets in the R.A. Dickey deal. Grade A-.
The knock on Syndergaard has always been his breaking ball, which needed a lot of tightening. That said, my research indicated that his breaking ball looked much better in the second half for Lansing last year, which I alluded to in the book by saying his curve was underrated.
Well now we have more information about that. Check out this video interview at MetsMinorLeagueblog.com, where Syndergaard tells interviewer Toby Hyde that the Blue Jays taught him a slider last summer. But it wasn't just adding another arsenal option that made a difference: Noah says that working on the slider had the side effect of adding power to his curveball, dramatically improving the pitch. That fits the reports I had from the Midwest League late in the year.
Syndergaard also makes some comments about his mechanics, and there's a good look at him throwing in the bullpen. He's also really tall; he looks bigger than his listed height to me.
In any event, there's nothing there to make me change my mind about him. He remains a personal favorite.