Thought I'd try to bring some new life back to my aging MacBookPro 2.53 Ghz, 15" Unibody MB471LL/A 320 GB HD 4GB Ram. It's been problem free except the keyboard back light quit working just before my apple care expired and got it fixed under warranty no charge. I replaced the stock 4GB 1066 MHz DDR3 SDRAM (Two 2 GB modules) with OWC 8.0 GBDDR3 PC8500 1066MHz kit (4GBx2) Also replaced the stock 320 GB HD with the 240 GB OWC Mercury Electra SSD I had downloaded and installed OS x 10.8 mountain lion on the MBP a few weeks ago from the APPs store and saved a copy of the file after the download to my desktop and burned a bootable USB OS x flash drive.I restarted the MBP after the upgrades and held the option key and selected the the USB OS x boot drive. Launched disk utility and formatted the SSD drive......installed OS 10.8 via USB flash drive and restarted fine after the OS x installation.Connected the WD 2 TB external hard drive via the thunderbolt cable and the time machine backups started and completed. The MBP works great!!!!! Seems snappy and programs open much quicker.I noticed the bootup time when I did the restart was really quick compared to the old MBP. I downloaded the Blackmagic Disk speed test APP and thought it scored low and I'm having some buyer's remorse thinking maybe I should return the OWC 240GB SSD for a refund and go with the Samsung 830 256 GD SSD ? Not sure how to post the Black Magic Disk Speed results but the the write speed was 134.4 MBS and read was 208.0 MBS now I didn't do the test before hand using the original 320GB 5400rpm HD but did test my 2012 mac mini 2.6GHz I7 8 GB ram 256 SSD and get write speed 408.9 MBS and read 448.3 MBS.