I have a 2009 15" MBP that I'm thinking about replacing. I'm currently torn whether I should get a base 15" cMBP with 4GB memory & 500GB HD or the 13" cMBP with the i7, 8GB memory & 750GB HD. I would upgrade the memory on the 15" on my own. I really don't want to spend more than $1,800 on the machine. I use the laptop mostly for email, internet, music, videos, pictures, word processing, spreadsheets, etc. Nothing heavy duty. I'm just not sure about the smaller screen size. Has anyone downsized and regretted it? Or anyone who's bought the 13" only to later wish they bought the 15"? Any other configuration suggestions within the $1,800 max range? I'm not sold on the retina display with the smaller flash storage for this price point. Thanks.