It is indeed noticeable. I was considering returning my SSD after reading the horror stories. I even popped it out and put back the normal drive. After using my mac for all of ten minutes I couldn't stand it. I popped the SSD back in. Once you get used to the SSD being there, going back, at least to me, is impossible.
I'd say the SSD is the most significant upgrade you can make on your laptop these days. I was skeptical when I read others saying that. Microsoft Outlook in particular is so slow without an SSD. With a regular hard drive, the first launch of it after a boot is extremely slow. It must have been 6 or 7 bounces to start. If you quit it and then re-launch it, it opens in one bounce. With an SSD drive, first launch or second launch, it doesn't matter. You won't get to half a bounce and the app is already running.
With an SSD, everything pretty much feels like it's already loaded and you're merely switching to it. It's that fast. At least mine is. And once you get used to that, using a machine without an SSD feels like you are using a machine from 1995. You will right away find yourself wondering why it takes so long.
Boot time is that way too. It is dramatic to see the difference without an SSD. We have these nice Core i7 quad processor cores. Lots of RAM. But the hard drive is indeed holding it all back. The hard drive feels like it's a decade out of date.
What I'd like to see going forward are the loss of horror stories. These SSD drives need to become so reliable that even the worst bargain basement units from a used electronics store should be good for many years of solid use. The technology needs to become bullet proof. Because once you own one of these SSDs you'll find it very hard to go back. I want to put an SSD in my iMac now. I've been thinking of putting together external SSDs for backup rather than traditional hard drives in FireWire cases.
Speaking of external hard drives, we need SSD in Thunderbold 2.5" external cases for back up. No more of this slow FireWire and USB. I need to a minimum of 250 Megabytes a sec now.