Oh, huh. Guess I can stick with my current tires! Seriously though, I'm not sure if the rr difference between 25 and 23 is enough to overcome the (very slight, yes) aero penalty of the wider tires? I'm running 25c GP4000S IIs right now on wide rims (H Plus Son Archetype) and they are pretty damn fat. I haven't gone to latex tubes yet, though I am on thin butyl tubes. I'm a little paranoid about running pricey tubes all the time, since I don't change wheels between training and racing, but I am thinking about it for next year. I flat rarely enough that I don't think it would be too expensive.