This is probably on here somewhere but I haven't seen it and if it isn't, it needs to be....link to second gen 4.7 Superchips dyno sheet. Seems like there have been several threads where this has been mentioned or referenced so here it is.
As you can see max gain is 23hp and 34tq. Not bad but also consider max power comes about 1000rpm lower with the SC. Also notice the roughly 20hp difference at just over 3000rpm and over 50hp between 4500 and 5000. Torque looks to peak at about the same rpm but notice the roughly 50ft-lb difference between 4000 and 5000 (except for the spike in the factory graph at about 4300) and both the SC hp and tq graphs are much more linear.
Hope this helps with any 2nd gen owners on the fence about a programmer.