Thank you all for the very thoughtful responses. I got a deal this summer on some 700x28 Continental Ultra Sport IIIs and they have made a huge difference over the stock tires. I'll save the money for maintenance and touring trips next spring. I think I've got the comfort fairly well dialed in. I'll keep after training during the winter months, as well.
Regarding the comments on reducing wind resistance, how much do you focus on clothing wind resistance when touring or randonneuring? My clothing choices are admittedly not terribly aero, usually athletic fit t-shirts.
PS: Those dynamo-hub wheels are awesome! As are the pictures of the Volpes fully loaded for touring!