I've beaten both versions (the PC one many, many times, too) and I think the PC version, while having many really appaling flaws, is a much better game. The PSX music is awful, the combat is awful (whereas on the PC version it gets legitimately challenging and interesting while still remaining fair if you play on the hardest difficulty). The environments in the PSX version are hardly better than the PC one, still a lot of straight tunnels with different visual dressing, but nothing else, unlike the PC version which had a lot of huge cavernous areas and some very different layouts from "a corridor" in many places.
The storyline, though, is better told in the PSX version, in the PC version parts of it are kinda forgotten and not mentioned at all. Kevin Conroy voices Drake in both versions, though the PC version has a lot of really so-bad-it's-hilarious NPC voice acting to laugh at also.
I have a full playthrough of the PC version on the hardest difficulty on my youtube channel (same as my username here), and a recorded stream of me going through the PSX version for the first time (and possibly missing a lot of gameplay nuances - for example, I never managed to figure out how to properly block with a shield). That is if you want some reference for comparisons.
