i have several and i would not trade my 24's for anything. (i also have a 16 for other reasons).
you lose quite a bit of velocity with the shorter barrels, but in some situations it may not matter. i tend to shoot longer distance so i want everything i can get out of the 223. i used to take my 22-250 when i thought the shots would be long, but i am so comfortable with my ar that i seldom take anything else.