I've changed two more things on Jake: brakes and the front fork.
I replaced the P2 steel fork with a Ritchey carbon one. The P2 ended up being lighter than I'd expected, but I still managed to save about half a pound.
As I was getting some shuddering I couldn't seem to adjust out of my canti brakes, I found a deal on some tektro mini-v. They work great with my brifters, though there is one little sorta-issue.
You only get about 1mm of clearance per side, so you have to make sure your wheels are true (not a problem here), and my 32c tires won't clear the pads when removing a wheel unless I deflate them.
For fixing flats on the road, that's not an issue, I guess... but if I'm hauling the bike in the back seat of my car and have to dismount the wheels to fit, a couple minutes of extra labor.

Functionally, they seem to be working well, are quiet and stop me fine. If I was living in a bicycle safe area, I wouldn't give it much thought, but right now I have to haul my bikes to ride.
Sold my HHR with the hitch receiver, guess I oughta start looking at installing one on the K-Pop Cruiser (Hyundai Elantra).