Go with the TH .75. I am 100% satisfied with mine so far. With over 3-1/2 gallons through it, with not one dead stick "knock on wood" and still on the same #8 plug that I broke it in with. I am running a Bisson pitts made for the TH .75/GMS .76, and have had absoulutly no issues what so ever with this engine. I would not hesitate one bit to buy another.
Currently I am turning an APC 12-8 @ 11,400 richened for flight. The performance of my 7-1/2lb Shoestring has with this combo is quite spectacular.
Just the other day, I fellow at the field asked if I had stuffed a 1.20 in the plane, when I turned to him and told him it was a $90.00 TH .75, he just shook his head and walked back towards his plane.