I have a MacBook Pro i5 mid 2012, the last non-retina model, I upgraded it to 8gb ram and a 120gb Samsung 840 evo SSD and the performance is awesome, but someone offered me to trade his MacBook Air 13 mid 2013 for my MBP. The MBA has a better battery, slightly higher resolution screen, it's much lighter and thinner and it has Haswell processor already, but there is just one thing that concerns me, it has only 4gb of ram and I know it can't be upgraded. I am a web developer and use mostly Photoshop, Coda, MAMP and other normal apps like Chrome, Skype, Thunderbird, Spotify. I remember when I had 4gb ram on my MBP and sometimes it slowed down and the memory pressure went yellow, but I had a normal hard drive, so the virtual memory is much slower in that case. Is it worth trading mine for the MBA? Would the 4gb ram be a problem in the future or the pci-e ssd works well when it needs to be used as virtual memory? Thanks!