Well, I absolutely LOVE my new Penryn. Going to the 2.5 Penryn, from the 2.2 Merom, was a good decision. It is a good bit faster all round, and I'm particularly impressed with the graphics improvement - a 1080p movie is now 100% stutter-free, whereas on the Merom it wasn't (4GB, 7200rpm HD on both). Also, Mac OS animations are 100% fluid now, I've never seen this before on any Mac I've owned - I have all my data transferred across (75GB left on my 200GB HD), and dashboard is so smooth when it fades in/out, exposé, etc., I've always experienced even just slight stutter on other Macs. Anyway, what I AM concerned about is games performance. I've directly tested Unreal Tournament 4 demo, (Mac version), on my Penryn and Merom (and even PowerMac G5 single 1.8!), and the Penryn slightly stutters constantly, at the same res and settings as the Merom, whereas the Merom is 100% smooth. I find this really odd, and it's the same in other games as well. For instance Lego StarWars II (Mac) performs fluidly at full res/settings for about 4 seconds, then it stutters for a few seconds, then goes fluid again, etc. It doesn't seem to matter what's going on in the scene, it just does it. Also, the "flurry" and "arabesque" screensavers stutter slightly as well. I just find it weird with exposé/dashboard etc. being perfect. Can anyone help?