So, I've had this machine for awhile now and forums keep saying to wait for a software update... Well, 10.8.3 is loaded and this machine is still jerky, choppy, and slower than a 2011 MacBook Air. I brought it to the Apple Store today, they ran tests on it, and it appeared to be normal. I showed her the jerky menu scrolling and she chalked it up software. I don't know if there was frustration in my voice or what, but she said she would like to send it out to have someone look at it more. I bought this computer the second it came out... Do you think it is more a hardware issue or software? I'm not a big fan of completely erasing a computer and starting from scratch, especially when it has been like this since new. Thoughts?