To fill in some info here... I originally got my tune from PCM4less. I must be the only person to have ever gotten the shift firmness level 1. This is my daily driver, plus my wife has back injuries so I can't go too aggressive with it. I have also towed a 5500# trailer up the mountain, so they left in some of the torque management. I opted to keep my original PCM, and buy the unit they sent me, however I never had a reason to put the original PCM back in the vehicle.
A couple years later I bought HPTuners so I could really dig into it (and for all the things I've changed and would have required a re-tune, I've probably broken even on the cost). From my original stock tune file... RPM cutoff is 5100 while parked, or 6300 while moving. Speed limiter is set to 104mph. I have a 2004 TB LT SWB.
The original tune made a very noticable difference for me, especially in the shifting. With the stock tune, I had to manually shift when merging on the highway to prevent early upshifts that killed my accelleration. The tuned PCM had me shifting almost exactly where I would manually shift at, so I didn't need to keep my hind on the shifter all the time. Even at a firmess of 1, there was a difference... crisper and faster shifting without jerking... perfect for a daily driver. The ONLY issue I ever had with the new tune was while driving in construction traffic. The 1-2 shift at times would practically launch me forward, and prompted me to spring for HPTuners so I could make my own adjustments.
One thing to consider when picking your shift firmness is what gears you have. I'm betting nearly everyone who opted for the level 2 or 3 firmness is running 3.42 gears (or much larger tires). Last Fall I swapped my 3.42 gears for a set of 4.10s, and I immediately had to return the firmess back to the stock levels (note here there are two different tables, one controls firmness, the other controls shift speed -- I still have a fast speed set, but no additional firmness). With the additional firmness and the 4.10 gears, I was actually squeeking the tires on all three shifts on the highway, and in 4LO the 1-2 shift was so hard it felt like the transmission was going to tear itself out. The point of all this is that there will be a difference in the apparent firmness depending on what gears you have.
I can't imagine anyone wanting to go back to a stock tune, the vehicle simply drives much better with the custom programming. If you are trying to decide whether to buy an extra PCM, the only question should be "what will you do with it?" I keep mine on a shelf as an emergency backup. The only time I ever kept it in the truck was when the dealership was trying to reprogram my PCM for the gear change, and we weren't certain of the effects.
I've been over 100 with no tune.
