Tormek has improved the SE-76 jig. The old SE-76 worked well but if for any reason your cutter did not grind square there was no adjustment to square the grind. The new SE-77 addresses that problem and brings in additional capabilities such as grinding cambers and makes it easier to grind irons with out of square sides like some older chisel and plane irons, and it can hold many Japanese chisels as well.
By adjusting two outside screws you can adjust the grind to square but even better if you loosen the two screws you can grind a camber on the cutter. How much camber depends on how much you back off each screw. With the screws fully backed off it will not grind a scrub plane camber but does a very nice Jack plane camber and with a slight back off of each screw you can grind to a perfect camber for finish planes.
If you have a Tormek or use Tormek rests and jigs the SE-77 is a great improvement over the SE-76.
Here is a photo of a max camber iron using the SE-77 jig.
camberedIron171129dscf2202.jpg
The SE-77 jig combined with a 10' CBN wheel makes me want to keep my Tormek.
ken