I have a Powermac G4 dual 800 Mhz that boots faster than the latest generation Mac Mini with Snow Leopard. Its an amazing machine up to this very day.
I love SL but am so glad that its not available for PPC. It would have been a disaster - the RAM management in SL is screwed up majorly. 🙁 On the PowerMac with 1 GB RAM I can have 20 Safari tabs open, Photoshop CS running and Skype without major hiccups. On my Mac Mini (4GB RAM), as much as I love and adore the system, its a pain after the paging out begins.
So yes, do enjoy your Powerbook and remember that its from an era when Apple did MORE with less (CPU power) so their systems HAD to be optimized heavily to run like champs.