Just installed a Samsung 840 500GB in my late 2008 MacBook Pro (2.8GHz Core 2 Duo, 8GB 1067 DDR3, OS X 10.8.2). Purchased the standard version of the 840 SSD, not pro version. Installed in the main drive bay next to the battery. Getting 210MB/s read, 270MB/s write out of the box without TRIM enabled. Same EXACT speeds with TRIM enabled via Trim Enabler app (after restart). Guess I will leave it enabled for now? Any recommendations here?
Repurposed my old HDD with an OWC Data Doubler in the DVD optical bay. Carbon Copy Cloner to selective clone to the SSD for initial setup without any issues at all. (Never have had any issues with CCC - it's a fantastic program.) Using the optical bay HDD for media, photos, large file storage, etc. Have original system HDD in USB enclosure that I'll be using for backup/clones of the SSD.
So far extremely happy I did this. Quieter, cooler, faster. Battery life has been phenomenal on this older laptop so far. Definitely longer lasting than with HDD/DVD previously. Did not do any hacks for shutting down the HDD sooner, etc. Left power settings alone and managed in the OS.