I have a Wise head on my ST II and it works very well. I purchased at extra cost the adapter that goes on the mounting bar which elevates the tension head so it is pulling at the same level as the racquet. The trade off is losing 360 degree rotation but I have not found that to be a great sacrifice. You could just buy the tension head without the adpater and you would still have 360 degree rotation however the head would be pulling down on every pull which is not the ideal way to pull the strings. You need the mounting adapter as well when purchasing the tension head. It cost $45.00 extra.
My ST II with the Wise head works very well. The Gamma stringer is well built, the all metal clamps work well and are easy to adjust, and overall adding the Wise tension head to this stringer is the most cost effective way to end up with an electonic linear pulling stringer. I would strongly recommend this combination to anyone that is interested in doing it.
