I too just joined Team Power with my used iBook G4 12" 1.33 GHz. My first Mac was one of the Santa Rosa Macbooks, it was nice and faster than my iBook, but the 12" book actually fits my lap(I'm extremely skinny), and I've been constantly surprised by it's speed, in spite of reports it actually handles Youtube well, not to mention other common tasks. What's more this is all from the perspective of Tiger, I could easily upgrade to Leopard with it's 1.5 GB of RAM if I felt the need for greater software support, which I currently don't.
I appreciate the aesthetics of pre-Leopard OS X far more than current versions, again it's that warmth, and the first macs I used were all either Panther or Tiger. In an ideal world I'd have the pinstripey interface of Jaguar/Puma, but going back further than Panther almost never makes sense.
For a reason I haven't seen yet: as I learned more about computers and computing history, I became increasingly perturbed by Intel's anticompetitive nature, I would say it may even be worse than Microsoft at their lowest low. Look up the history of the DEC Alpha and Intel Itanium CPUs to see what I'm talking about. Combined with the fact that there were alternatives in the POWER world at the time of the Intel switch, such as a Freescale dual core G4 efficient enough for laptop use, and the current state of the POWER cpu(look up POWER7) I think the switch was a cowardly cop-out meant to make the Mac division more "autopilot" in preparation for increased focus on the upcoming iPhone, and Steve's forseen potential health relapse.
I would be a bit more hospitable to AMD based Macs, though I'd still be indirectly supporting Intel by supporting the x86 and x86-64 architectures. I have mixed hope for these rumors of ARM powered Macs, I fear them being more iOS like or locked down, but ARM is very efficient and has many of the same advantages as POWER. Of course, ideally I'd wish them to switch back to POWER chips while there are still some vendors shiiping universal binaries, and the functionality is still in xCode, not to mention POWER7 chips with AltiVec are a great fit as far as I can tell, the frequencies can be scaled back a lot to accomodate thermal and power sensitive environments.
We'll see how it goes, until then I'm probably going to grab a Powermac G4 and use an aftermarket dual 1.6 GHz G4 card and an SSD to trick it out. If anyone has one how do they compare to the G5s?