My m7 was delivered yesterday, haven't had a chance to do proper gaming tests yet. Will do it later this week. Note: I played all games under OSX.
I had the time to test three games.
I started out with Minecraft, the internal display scaled to 1440x900 - that's the resolution Minecraft played in fullscreen. I got about 40-50 fps, after a while the fps dropped down to 20-30 (I guess it was throttling) and then back up to 40-50. It was fully playable and the throttling didn't last long. I will try it at lower resolutions later on. 1440x900 was fully playable for me though.
I had a stab at Left 4 Dead 2. I played around with both resolution settings and graphics settings (shaders, shadows, model detail etc) - via the l4d2 console I showed the fps, but it fluctuated a lot, so hard to tell what I was getting. The game however felt pretty smooth at 1172x720, all shaders, details at low. Did notice some stuttering here and there. Will test more later this week.
I played Syndicate(1993) in dosbox. In windowed mode it was unplayable, the mouse cursor lagged, everything played in extreme slow motion. Turned on fullscreen mode and suddenly the game ran at full speed, no stutter.
I have Starcraft 2, Diablo 3, World of Warcraft to test later on + quite a lot of games via Steam.