FYI - awhile ago I bought the Performance back band for my WD12 so that I could have a higher seat back. This year I have taken it out on three trips and enjoyed it.
It is ment for a SOT but I cut straps and attached to the yak, though I should have left a little more room to adjust in the back. It does stick up above the deck so for those of you that use a skirt it could be a problem- but I wanted a higher back. It gives me the option of leaning back for a change when I get tired paddling leaning forward.