OK - Tennoning Jigs. Any recommendations?

Considering

$79 Shopfox Woodstock -
http://www.grizzly.com/products/item...emnumber=H5782

$85 Delta 34-183
http://www.amazon.com/exec/obidos/tg...86427?v=glance

$109 Jet 708111
http://www.amazon.com/exec/obidos/tg...&s=hi&n=228013

$106 Rockler http://www.rockler.com/ecom7/findpro...=10185&clk=412

I did a Google search and read the comments about quality of the delta and
that the Jet and powermatic are identical. I have not read anything about
the shopfox or rockler. I did see some previous posts about having to tweak
the miter guide rail on some saws. I have a Grizzly 1023 right tilt. I'm
thinking the shopfox should be as close to plug and play. Are the slot to
blade measurements the same on Griz and Delta and PM?