I have a early 2011 15inch mac book pro with 4gb 2ghz i7 intel hd graphics 3000 500gb storage and a Dell Inspiron i7359-4371SLV 13.3 Inch 2-in-1 Touchscreen Laptop (6th Generation Intel Core i5, 8 GB RAM, 500 GB HDD + 8 GB SSD..which one should I keep and upgrade? (mac is older but I think more upgradable)