I have a similar issue with my base 11 (other than a 128 GB SSD). I was using Chrome, but switched to Safari as it hangs a bit less. I also found installing the AdBlock and ClickToFlash extensions helped a lot.
When the 11 inch first came out this was mentioned in a few threads, and the general conclusion was an update is needed to the Nvidia graphics drivers. We'll have to wait on Apple to do that though.
Try the above steps out, that should help some.