Rebuilt 4L80E not shifting properly

[4x4soldier]

I have a 1999 GMC 2500 4X4 with a 6.0 and a 4L80E. A few years ago I had the 4L80E rebuilt by a pretty reputable local shade tree mechanic. He came highly recommended. Anyways ever since I've put the transmission back in the truck it doesn't feel like it shifts right? It also feels like it doesn't take off in first either. The truck is also pretty sluggish. Been thinking about trying an ODB2 programmer to try and get better control of the tranny. I probably have 5K on the transmission now and I've tried a lot of little things like changing the filter and fluid(which looked great). Unplugging the tranny and battery over the weekend. Nothing seems to wake this thing backup? Some times if I press the Tow/Haul button the truck seems to be a little better, but it's still not it's old self.

idea's?

 

[sexxy]

Wrong torque converter? Does shifting bump or slip from gear to gear?

 

[4x4soldier]

I don't think it's the torque converter? Could be but it pull's and holds pretty decent. And no it doesn't skip out of gear, it's mostly just from a deadstop and then thru the upshifting process it just feels lethargic. I've pulled our boat with it and it does ok. And when I put it in 4 wheel drive it does fine, it's primarily from a dead stop thru acceleration. It hold's speed fine.