Hello: I am currently using Macbook Pro 15, early 2011, 2 GHz. I have 16 GB of RAM installed. I am considering upgrading for these reasons: - no USB3. Thunderbolt seems too expensive, I think a RAID box with USB3 will be perfect for extra storage - DIY Fusion drive does not work in this model, as reported by few members - not sure how reliable would a SATA3 SSD be in this model - it's a bit too big for travel. I am a software developer, semi retired, but I want to get back to few projects. I need Windows as well for some mobile phone tools ( diagnostic monitors, RF planning, etc ) , currently running VMWare Fusion. Most of the time I am on an external monitor. I am wondering if the Macbook Pro 13, 2.5 GHz i5 would be too much of a decrease in raw CPU power. Geekbench seems to indicate appr. 60% of CPU power compared to the 2011 15. The Airs do not support 16 GB of RAM, and the 15 inch rMBP is too expensive. The first thing I'd do is install the DIY Fusion drive ( extra SSD, HDD into CD bay ). Anyone with experience in this transition ? Thanks for any info. PaulCC.