I have to agree with TDIMeister as most people do not hop from one tuner to the next on their car.
I did have an Upsolute tune on my car as back in 2000 it seemed like there were not many options. Then I found out about RocketChip and then I went with RocketChip. Within one tuner there is a little difference in how the tune feels and the tuners tend to get better and better at what they do. I liked RC1, then RC2, RC3 was really nice to drive, then new turbo and RC4 and I can see Jeff is getting very good at this as I can see things that are in the tune based on how my boost gauge responds: it is like my boost gauge has a peg at 26 psi unless I really change conditions quickly I can get it to jump to 30psi.
Yes my car with RC3, stock turbo, and pp520's was just shy of 140hp, with RC4 I am 150hp and 250ft-lb torque,