After this morning's MBA release, I've decided to get an MBP. However, I'm not sure which one. I know I'll definitely upgrade the stock setup to a 128 GB SSD, but other than that I'm unsure about which one to pick up. I have a few questions that will likely determine which one I buy: 1) Is there a major performance difference between the 2.3 i5 and the 2.7 i7? 2)Does the 2.7 i7 drain the battery faster? If so, how much faster? 3)If I upgrade to 8gb of ram from the stock 4gb, will I see a performance difference in day to day usage? 4) Finally, will more ram drain the battery faster? Thanks!