Depends what you're talking about. A HVA 1600/1640 is different from a P-H as it's a small ring action, but the HVA 640 (m/98) is pretty much the same as a P-H, as both are based on the commercial m/98 (FNH vs "Santa-Barbara"). In my experience and opinion, the FN actions are always a bit better fitted and finished than the S-B action, but it's a marginal point.
But there's also 640s based on m/94/38, which, then, are different animals.
Most don't realize that the FN "commercial" M/98 appeared three years after HVA introduced their own "commercial" M/38 and that the 1600 action (introduced 1953) preceeded the FN Supreme (introduced 1956), which, at the end, is pretty much a copy of the streamlined 1600... and the Santa-Barbara / Zastava duo are, themselves, based on the FN Supreme...