The specs: Core i5 (quad) 2.7 GHz, 8 Gb of RAM and an AMD Radeon HD 6770M with 512 Mb of GDDR5 VRAM. Oh, and OS X 10.8.2 ...
I've played a bit with the advanced video settings (both from the game launcher window and editing the user.ini file). I've followed geforce.com's "Witcher 2 Tweak Guide" and tried a few tweaks I've found here and there (IMG, Steam, GoG, Mac Games Store, ...).
Well, I'm a bit disheartened ... I can barely play the game at 1280x720 with very very low settings ... 15-17 FPS.
A lot of details are lost this way and I find it hard to play the game (I'm getting older and I don't have a good sight).
I understand that the RED Engine is pretty demanding but ... I was wondering how many Mac models will be able to play this game in the coming months. Even the (upcoming) new iMac lacks a decent GPU (only the $1,999 top-of-the-line model will offer a rather interesting BTO option: it will be possible to choose between GeForce GTX 675MX and 680MX). I hope that Virtual Programming will be able to shorten the distance between the Windows and the Mac version of TW2 one of these days. But I won't hold my breath.
In light of the above, I really think that the XBox 360 port is amazing (especially given its age).
Don't get me wrong ... I really appreciate CD Projekt's attempt and I'm glad they made the decision to port it. It's mainly Apple's fault (and maybe VP could have done e better job).