I stood almost all the time from my Meyers Sportspal S-15, more stable I suspect than any kayak up to that same length. I really liked it. But, I added a high seat to the canoe's gunwale seats and it put my knees at a right angle which was plenty high for most things other than flipping and pitching or making long casts. Now, in a Propel 10, I rarely make long casts . . . I can just slide right up where I want to be. I do stand but more now to stretch my legs. The seat is so comfy that I rarely even need to stand up. But, yes for flipping and pitching: a big advantage.
I sure am impressed with the new Slayer Ultimate FX Propel 13 since it positions "feet below water line" for a lower center of mass. Odd looking, kind of creates that Tim Conway comedy skit short legs look. Ha!