The medium is a great toy with the 22. Chicken parts never cooked better than with this thing. Fill it with lit coals, surround it with chicken parts, wait 25 minutes, done.
The small Vortex also works on a 22, with smaller results. Lower heat levels and circulation.
The medium will also work on a 26 fairly well. The kettle temp will be a bit lower - longer cook times on chicken parts. But the 26 and the medium Vortex is a great combination for higher temp "baking" cooks. Cornbread, casseroles, or whatever cooks at a higher temp in a larger pan that fits on a 26 and not on a 22. The convection created by the Vortex gets food cooked and brown on top.