I only have the smaller SnS and use it all the time in my 26er. AS mentioned, the only possible drawback is that the bigger one hold more charcoal. On the other hand it, consequently, takes up just a little more grate real estate.
If you are only going to be using it in the 26er, then I think it's a coin toss. But if you will be using a SnS in both, then, to me anyway, it makes no sense to buy 2 of them. Get the 22 . . .
BD