It's funny I work as a salesperson in a computer store, and yesterday a potential customer tried to argue that solid-state drives were inferior to regular hard-disks as they are less reliable. I didn't bother arguing i just said "sure" then laughed at her expense later on.
I think the issue is that SSDs have a finite number of writes, and before TRIM was implemented performance degraded considerably over time. And OS X still does not have official TRIM support for non-Apple drives.
While hard drives are obviously prone to failure, many people have old hard drives running well beyond their expected lifetime, and they were probably not aware of how unreliable they can be. (and modern drives are pretty good)
Honestly though, I do think its a bit overhyped. I have a SATA3 SSD which maintains speeds above 500MB/s (often 550MB/s) in most scenarios and while its definitely faster, with tasks like launching applications in normal use (rather than launching every app on the system at once, as people seem to like to do when they get an SSD
) it is not significantly quicker than a modern desktop hard drive. Youre only talking about saving a few seconds with more complex stuff like Photoshop. Most of the time youre still waiting for the CPU.
With plenty of RAM in the system, how often are you actually quitting apps, or shutting down & restarting? I sleep all my computers, theres no need to shut down any more.
Dont get me wrong, I prefer to have it as a boot drive and running games off it, but its not like I could never go back.
Everything but the highest density notebook drives are quite a lot slower than a desktop HDD though.
If youre going from an old 6080GB notebook drive, I can definitely see the difference being quite noticeableyou would also notice a big difference moving to a 750GB/1TB drive though.
But it does not make an old machine feel like new. Putting an SSD inside a MacBook 1,1 which maxes out the SATA1 bus at all times, is certainly quicker than the old HDD when launching apps, but it still feels like a slow computer.