I bought a C300 a while back, and it's been working pretty well. I'm not sure if I would buy the same drive if I were to do it over again today, though, since my original logic was that Apple would be sure to implement TRIM support soon, which all reviews seem to indicate that the C300 requires to perform at its best. Nowadays, Apple
has implemented TRIM in 10.6.7, and for some incredibly frustrating reason they have artificially limited it so that it is active only when using Apple's preinstalled SSDs and not third-party ones like the C300. Now with that said, my C300 is still performing well almost a year later, and I'm pretty sure I've got to have written to the whole thing by now, so perhaps Crucial's garbage collection is better than the Internet makes it out to be. Still, though, if you want to be completely safe about it, a SandForce-based drive may be the way to go since they are supposed to handle the lack of TRIM support much better than other drives according to reviews.
Here's the performance my probably written over by now C300 is getting at the moment:
Not as good as brand new, but not
bad per se.
Here's my MBP's original hard drive, in a FW800 case, for comparison:
Gotta love those random 4K speeds.
Anyway, the current gamble with the C300 is no longer how long it will take Apple to implement TRIM, but rather whether they will do it at all for third-party drives, or whether they will exhibit a case of the classic Apple stubbornness and decide you don't need it.

With a Sandforce-equipped drive, you'll have a little less usable space, but more peace of mind that it will continue to work just as well as it did on day one.
As far as installing in a current MBP goes — it's dead simple, and if you can operate a screwdriver, you can replace the hard drive in your MBP. As an additional bonus, get an external USB or FireWire enclosure for your old internal hard drive, and then you can use it for a little extra storage if you like.