I alternate between enjoying the cushy traction of 35s (!) and longing for the zip of 23s. A good solution I recently discovered was to ride the 23s while neglecting to adjust the cups & cones in my rear wheel, then switch to 35s and clean up the rear hub at the same time. Now the bike seems way faster, even with the fat tires.

(It's sort of pitiful that I can trick myself so easily.)