SSD's...like getting a brand new Macbook Pro.
I've had my early 2011 Macbook Pro since launch. I've been exceedingly happy with the performance thus far, the HDD never gave me any issues (stock and upgraded one to be more specific), and the overall feel of the computer never seemed like it broke a sweat, even under heavy load.
I have the 13" i7 model that i upgraded to a 1TB internal HDD early on (when SSD was still a ridiculous premium upgrade that i just couldn't see myself getting into at the time), and also went from 8GB or RAM to a recent boost to 16GB. I do graphic work as well as some website development to go along with daily use as my personal computer in my cruiser in my day job (law enforcement). She's been a trooper, just like my previous Macbook was, and i had ZERO complaints.
Then SSD prices took a nose dive, and a few months ago i decided to take the plunge. Let me tell you that when it comes to upgrades to computers, this has got to be the most amazing and noticeably legitimate improvement i have EVER done to my computers over the last decade.
For starters, i was not fully sold on the booting and application management speed people were showing online from their own SSD upgrades. I'm here to tell you that above and beyond anything, watching my computer boot up some of the hefty programs i use in a split second is a joy, pretty much anything in CS6 is open and ready to go in about a second, which is just phenomenal.
The boot up time is pretty cool too, though i may have had the naive approach that my computer was going to be an "Instant on" kind of deal like the iPhone or iPad, and that's not quite the case (though it is super fast)...it's blazingly faster than the boot up time from the HDD, which really wasn't that bad to begin with.
Overall, if you're in the market to do this but haven't yet and were waiting for someone to give you that little extra push...let me just go ahead and push you over the edge on this, do this TODAY if you can, you won't regret it. I opted for the smallest available for my machine because, honestly, i have a ton of internal storage that i don't really need and so much external storage at home i can't imagine the need for actually saving everything on my machine at any one time.
With the prices today, this is probably the best upgrade you'll do to your Mac's.
For those wondering, i used the Optibay enclosure with the Crucial 128GB SSD. Also got a handy little enclosure for my optical drive that turned it into a USB DVD drive (which i will still never use, lol).