Don't make me go downstairs and boot up my circa 2001 dual G4 Quicksilver! I think that thing is rocking 10.3
I also have a 2007 MBP, though that my have been the charger I sent to Billy so booting might be and issue since it hasn't had a battery in 5 years. It's what my Dell replaced 4 years ago.
Speaking of the Dell. It has progressed to telling me the battery has a 89% charge and 74.7% is the max charge capacity. I'm pretty sure that it's not giving me peak performance any more either as a 3D render that took 2 hours a few weeks ago has been running since 8am and it's now almost 9pm...
After lots of getting to the point of clicking the final button and then getting cold feet about a dozen times, last night I finally clicked the Please Rape Me button for a 16" MBP with the 2.3 i9 and 32GB of RAM. Now I have to wait until mid December because god forbid Apple recognizes that some things like more memory might be a common upgrade and have them in stock ready to go