You’ll find boot times and application launch times will get a nice, hefty boost from the SSD upgrade. A good example of this boost: when I upgraded to SSD from a 7200rpm spinner in my clamshell iBook, Tiger 10.4.11 boot-to-login-window time went from 1m20s, to 0m39s. That alone was worth the effort.
You’ll also find the main bottleneck, post-SSD, isn’t the SSD itself, but the IDE bus. Also, as you probably already know, maxing out RAM is another way to improve general performance.