I know exactly what you are looking for. I am looking for the same thing. I talk to jimIII and he is running 9's. I talk to other guys and they say get rid of the 5r55s and get a built 4r70w. I mean we have to make a choice, I't going to cost us money no matter which route we go. It's gonna cost around 5k to do a 4r70w swap, or 3500 for the tci 5r55s. ugh!
The 5R55S works well for my power level. I like having 5 gears and the low first gear. I dont want a manual valve body 4r70W or a seperate controller. I like the computer contolling the tranny in the tune. So the Level 10 was what I chose back in 06 and it has held up well.