This really should have been a fantastic buy; Silent Hill 2 is still by far the best best survival horror game I've ever played and Silent Hill 3 certainly has its charms.
The quality of the port though... I can't speak to SH3 (after an hour of SH2 I stopped playing and put in for a refund) but the SH2 port is pretty much unplayable. The frame rate lags badly if there's more than just James moving on screen, some of the cut scenes don't seem in synch with the dialogue, the controls are unresponsive (and not in the classic: It's SH2, the controls have ALWAYS been bad way.... they're worse). The game in general seems to glitch every now and then. It's not a fun experience. It may be less jarring if you haven't played the originals, or at least haven't played them recently. Play them close together though and the poor quality here glares at you, there's no way a ten year old game should outshine its HD re-release so completely.
I had a look about to see if / when this is getting patched, but apparently it already has in the US. And it didn't work... So I'm not holding my breath for a proper fix any time soon, if at all.
Some have said the 360 version is less buggy (not bug free...), so it might be a better bet if the option is there and you don't have the ps2 originals.
For shame Hijinx. It can't have been easy to do, but somehow you ruined a classic.
**Update: In case this is part of the problem... I played on a ps3 slim 250GB (1st gen of the slim I think). Also, there MAY be more than one version of the collection out there at present (just after launch) with one showing the bugs and the other not. In the former case: BAD PORT and maybe not fixable... or not easily / quickly. In the latter case, things may well get better once the defective stock is out of circulation. In other words maybe don't buy this for a few months or until there's word the issues are definitely resolved.