I have the 2011 15" Macbook Pro with 4 gigs of RAM, and the i7 2.0 ghz processor. I am having some serious performance/stability issues whenever I seem to use an app that does not say Intel (64 bit) next to it in Activity Monitor.... Well maybe not ALL of them, Google Chrome seems to work fine, but a few apps I've used recently that cause issues: -Google Music Manager - while uploading music system is very unresponsive and slow -Saabnzbd - While downloading and repair/unpack files, my system grinds to a complete hault. The irony of both these apps is memory and CPU usage is at a minimum. I haven't tested too many others, but these two are driving me nuts since I love them both and want to use them on the Mac. Could there be something wrong with my system? I'm assuming thousands of other Mac users are using these apps with no problems, but who knows.... BTW, I am wondering if it may have something to do with the Airport Wireless stack on the laptop rather then the app itself, because the Google music app maxes my upload bandwidth with my cable provider... And the SaabNZBD is just reverse of that, it maxes out download.. And no, I'm not running them both at the same time.