I cannot stress heavily enough how brilliantly fast MacOS is when running off an SSD. I thought windows was peppy when I put an SSD in my desktop. Since putting an SSD in my MBP, MacOS X went from a sluggish annoyance where icons bounced 5-10 times before an app loaded, to a speedy "no time to bounce at all" app start.
I did the same with a first generation MBP (bought in the summer 2006). I replaced the main HD with a Corsair V64, and replaced the optical drive with the old HDD with this kit[1]. The HDD now works in plain old ATA, but it doesn't matter. I use it for mass storage, not for speed.
The results are amazing. It takes:
- 21 seconds from cold boot to login prompt (and 5 more to get a responsive finder),
- 13 seconds to shut down, and
- 22 seconds to wake from deep sleep (2GB of RAM).
As you said, the apps launch almost instantly, including Office 2011 which was incredibly slow from the hard disk.