In the original game, if you turned Vsync on, the game would be locked to 30 fps. Is this bug fixed in the GOG version, ie. can I run the game at 60 fps with Vsync on?

I don't think so, because this bug was never officially fixed and GOG usually doesn't do extensive fixes other than getting older games running on modern machines.

Here's a guide to the operation referenced above:

http://pcgamingwiki.com/wiki/Dead_Space#Mouse_lag_and_random_sensitivity

I had to turn Vsync off in game and then go to the Nvidia 3d game settings panel and set Vsync ON there.

Then I could play at 60 fps. You can also supposedly use MSI Afterburner, but I didn't feel like starting another program every time I wanted to play.

Alright, the best option I found was using D3Doverrider for Vsync force and Msi Afterburner, then turning off Vsync in game & limiting FPS to 60 in RivaTuner Statistics Server. Now it runs like a dream, just the mouse crapola which I solved by just turning down sensitivity..

Also, hint for AMD/ATI users, DO NOT use Radeon Pro to tweak this game, Dxtory is fine instead of MSI afterburner, but Radeon Pro can lockout your access to your desktop in fullscreen mode, in a weird glitch that might require a logout or reboot to get out of.