8GB of RAM, especially with an SSD, should be plenty for most people. However those of us who tend to keep lots of tabs open in our browser and run multiple programs will notice some improvement with the additional RAM. That said, even though my desktop has 16GB and my MBP has 8GB I've seldom felt my MBP was at a disadvantage due to RAM. Then again, I don't use Chrome which I think is insanely RAM intensive.
8gb Ram For Macbook Pro Mid 2012
Crucial Tech and OWC (macsales.com) are my 2 hands down choices for RAM. Quality product and superior support.
Best Ram For Macbook Pro Mid 2012
Crucial Memory and SSD upgrades - 100% Compatibility Guaranteed for apple Mac Pro Mid 2010 - Mid 2012 (PC3-10600/4 DIMM) - FREE US Delivery. MacBook Pro 13' Unibody Mid 2012 Memory Maxxer RAM Upgrade Kit. PC3-12800 4 GB RAM Chip; PC3-12800 2 GB RAM Chip; PC3-12800 8 GB RAM Chip; Step 1 Lower Case. Remove the following ten screws: Three 14.4 mm Phillips #00 screws. Three 3.5 mm Phillips #00 screws. Apple MacBook Pro 13-inch Mid 2012 - Intel Core i5-3210M 2.50 GHz - 4 GB RAM - 500 GB HDD - DVD-RW - OS X Mavericks (10.9) Resolution: 1280 x 800 Graphics Card: Onboard.