I use a 2009 MBP with 4G RAM and 240G SSD.  Need to replace the battery.  Still going strong.<p>If I was buying new, I would go for an 13&quot; MBA with 8G  RAM.  The i7 upgrade is nice to have but not essential.  As for storage I would settle for 256G SSD and use a USB3 external drive for backup and non-active storage.<p>For me:
The 11&quot; MBA screen is a bit small and battery life a bit limited.
The MacBook keyboard bothers me and the 12&quot; screen feels smallish too.
My eyes are not that good, so the Retina screens don&#x27;t make that much difference.  YMMV.<p>Of course, if money was no object, then a 15&quot; MBP with the lot would be my choice :-)