Yep, they all about the same...
But you can make a pretty cool one if you want: http://www.woodworkingtalk.com/f27/tenoning-jig-modified-15905/
Than one rides against the fence, so if you fence is accurate and can be fine tuned in small increments, it will work fine. If not you're better off with a commercially made one with fine adjustment feature. :yes:
you'll find a few hours of enjoyable reading here:
http://www.woodworkingtalk.com/search.php?searchid=1404557
But you can make a pretty cool one if you want: http://www.woodworkingtalk.com/f27/tenoning-jig-modified-15905/
Than one rides against the fence, so if you fence is accurate and can be fine tuned in small increments, it will work fine. If not you're better off with a commercially made one with fine adjustment feature. :yes:

you'll find a few hours of enjoyable reading here:
http://www.woodworkingtalk.com/search.php?searchid=1404557