Need some advice here. In October I bought a refurbished 13" MBP (500 GB HDD, 4 GB RAM, 2.5 GHz i5 processor). I've really liked it but noticed it almost seems a bit sluggish at times. However, the new MBA's released yesterday at WWDC look amazing. (12 hour battery life ) Would it be better for me to: 1) Sell my MBP for one of the new MBAs. 2) Replace my HDD with an SSD and upgrade the RAM. Thanks for your opinion.