Recently purchased a hypertech programmer for a good deal and I gotta say I really like it. The power is really good, drive ability is awesome, shifting is much improved.
What surprised me the most is the difference between the 87 and 91 tune.
According to the hypertech dyno charts theirs not a huge difference but driving wise it's quite a difference especially under normal driving (2k rpm driving around town) or when I have two dirt bikes in the back. I have a Volant I'm going to put back on soon to see how it helps too.
My current setup is a 2010 gmc canyon crew cab with mid travel and 31" tires. Stock intake and exhaust.
I plan to get it dynoed in the next couple months to see where it's at.