First off make sure you get the model with the discreet ati gpu...6770 I believe... Also consider removing the optical drive and placing an ssd in its place for content playback. Hd is possible but I will not speak to how many layers other than to say more than 2 is possible with the correct hardware in my experience. Also... you CAN run Snow Leopard on one after jumping through some hoops. This has been my route and is working very well. You will need to compile or obtian a 10.6.8 image as it was never offered on a retail disk.