Well mine has SU7300 which is from an old generation of C2D, but I have no issues on any programs I throw at it ( Photoshop, Office...). On the other hand, first thing I've done with this laptop was a clean install of win7.
Seems to be an issue with the Intel GMA more than the i3, also it would help if it had more power. I also did a clean install of windows 7, Sony puts way too much bloatware on their machines.
I know for many hrs of viewing, 13.3" is better. 11.6" is great for travelling.
Is it easy to change out the hard drive on the Y?
Well, the 13 incher is not large either dude. It is quite small, just up to a personal preference. The HDD is easy as hell to replace, just pop open a tab in the back and the RAM and HDD are both there. I plan on putting an SSD in mine soon. It is also quite the looker.