Definitely one of the slower courts, surprised Agassi didn't win.
Not on this thread but at other times on this forum I've read the huge myth that all non-clay courts in the 90s were fast when that blatantly wasn't true. There were plenty of slow hard court events around and some slow indoor events as well like the Moscow Kremlin Cup. Overall there was a pretty healthy balance between fast and slow surfaces on the circuit, which I wish we still had nowadays.
Sampras was excellent on slow hard courts as well, and until pre 1996 played mostly from the baseline on the surface. Annacone then wanted to him to the serve-volley more on all surfaces and not just grass, so in 1996 he began to serve-volley regularly on 1st serves and stay back on 2nd serves. Then after his herniated disc injury in 1999, he became a flat out serve-volleyer on 1st and 2nd serves on all surfaces.
The funny thing is that people look at him beating Agassi all 4 times they played at the US Open, and Agassi winning both of their Australian Open matches, and assume that he owned Agassi on fast hard courts and that Agassi owned him on slow ones.
However when Agassi beat Sampras at the 2000 AO, the rebound ace was playing incredibly fast that year. The organisers had sped up the surface noticeably to help out Rafter and Philippoussis. Sampras served a career high 37 aces in their SF, and Agassi won a lot of free points on his serve as well.
Plus I would say that the US Open surface was medium paced when Sampras had his best period there from 1993-1996, including beating Agassi in the 1995 final. A lot of players like Ivanisevic complained about the US Open surface being slowed down in the early 90s, and with Agassi being US tennis's big star and other members of the fab four Courier and Chang preferring slower surfaces, you could understand the USTA's logic. In that period the USA were hosting Davis Cup ties on clay and slow indoor surfaces.
The courts there were sped up in 1997 and slowed down slightly in 2001, though they still played fast after that change.