I also just returned from the world, and noticed the same at most restaurants that I went to (19 TS meals). I also noticed that many times, when the server would catch a larger table (I was a party of 2 for 9 meals, and 1 for the other 10), my service would slow down considerably and the larger party would get much more personal attention from the server.
If the server did NOT have a larger party, most of the time it was just fine and a couple times, even with a large party, it was great, but it seemed a common trend that my smaller table (party size and/or total order) would get worse service than a larger table (even than a larger table ordering just drinks and desserts, as happened at Hacienda). This happened at buffets, normal TS, and even 2 of the 4 signatures that I went to.
While I understand that larger parties do need a bit more attention, a good server should be able to keep up a decent amount of attention to both the larger and smaller parties (there were times I had to go 10+ minutes with an empty drink making straw sucking noises (occasionally, not like I was constantly doing it) before I even got asked about a refill...)
I also noticed that at most of my solo meals, they were trying to rush me out a bit quicker (got the entree just as I started my app several times, and once even before the app!). While that's very much preferable to slow service in my book, it's still something to note.
Now, I will say there were some very good lights when it comes to the service as well, most notably as Crystal Palace (solo breakfast, on the 40th), San Angel Inn (solo lunch), Maya Grill (solo dinner), Flying Fish (solo dinner, at the bar), and Le Cellier (solo dinner).
(Reposted and tweaked. As original removed due to use of the "T Word" sorry about that, it wasn't intended to be the focus of the post)