Rennie, I have the 24" steel one from Woodcraft, it is darn good, and the price was too!
You are correct, the 24" one is good for most anything, even the Jointer, I used mine to check the set up I have, and it did the job. Of course, a longer one would not hurt, but I don't know how much I'd use it
Maybe others have something they can relate.
Cheers.......... the New Years Kind!
The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
William Arthur Ward