A lot depends on what you compare it to. Other boats of the same LOD? Same LWL? For sure the PSC water line is shorter than most boats of the same LOD. The will limit top speed. It also depends if you are talking about cruising or racing.
For racing I think the best you can do to compare is look at PHRF, for example PHRF New England - Handicapping - Base Handicaps
For cruising I think this article is gives the best answer you are likely to get: http://www.bethandevans.com/pdf/200mile.pdf
. It basically contends real-world cruising speed is purely a function of two variables: LWL and SA/D. So again, the short LWL makes the PSC slower than boats with a longer LWL.