The poor performance verses Windows doesn't surprise me. Consider, my Mac is about a year old; while it's a Pro model, it was the entry level model. Despite th

The poor performance verses Windows doesn't surprise me. Consider, my Mac is about a year old; while it's a Pro model, it was the entry level model. Despite this, the game plays well (no human perceptable stutter) at full resolution and settings. Valve isn't really motivated to optimize this game due to its age and how the current Mac hardware pool surpasses what PCs were (even accounting for the Mac platform's GPU lag) when Portal was originally released. The real proof in the pudding is when Valve starts to release Mac/PC dual releases like they've been hinting at. If they have the same problems Blizzard has getting decent performance for their hybrid releases, Apple might finally notice that their lagging on GPU support is a problem and not something they can continue to dismiss/hand off as the developer's responsibility. (I know... dream on.)