OK, I'm not sensing any consensus here. My choice is between kojak and comet because they both weigh around the same and that's half of the marathons. I can patch and change a tire very quickly but if it became a constant thing, then I would switch back to marathons. I think I just need to try one of the smaller slicks and see how it goes where I ride.
As for my friction drive (when it comes), "supposedly" it is designed to not eat the tires up. Again, something I will have to wait to see. If it does, then I can put a marathon on the front only, where the motor will be.
Does anyone actually have comets on their bike?