VERY long, sorry
You know, I ignored this for a long time. Now let me tell you a story.
At about 35K miles I found the VanAaken website. I was hooked, had to have one. I found the TDR looking for a VA. I lurked and read and lurked and read some more. I spent 6 months reading the back pages of the forums, and found a VA for sale in the mean time. LOOOOONG time member Jack N (Shooter) had one for sale, and I paid up. He had been through some adventures of engine and transmission types and was helpful when I asked.
I installed it and was told a hundred times that I was "at the limit". Well I was past the limit, it slipped the TC in OD like it was not there. I talked to ALL of the transmission players at the time, and was told everything from "it can't slip, you are feeling something else" to "it is going to die in the next week". DTT was the hottest ticket in dieseltown at the time and I had the cash for one. Called Bill to order a crate transmission and he told me "No ", that I should only pop for one when mine died or do a TC and VB install. He did not want to sell me the transmission because it was more than I needed to spend. I had the cake laying in the bank so I decided that the crate transmission I had asked for would be the way to go. I turned up the line pressure as high as I could without limp mode and drove on. The line pressure boost held for about 1500 miles, then the slipping was back like I never did a thing. OD was slipomatic gear. At least the fluid and filter got changed for the first time.
I wanted more power at about 40K miles. I called ALL of the transmission players at the time and talked to them. I was told by all that I was "in the danger zone" and most said "it WILL die in SHORT order". What the heck right? It is only money. I called up DD and ordered some DD1's. Put them in and took the VA off, it sucked. Put the VA and a boost module on and WOW I had a tire smoking beast. It was awesome. OD slipping was a real issue with just the cruise control, if I nailed it under the wrong conditions the tach would indicate as much as 600 RPM slippage. transmission was dead right? Nope.
At about 65K miles I wanted more power. LOOOOOONG time member Tom M (Briar Hopper) was selling an original Power Edge with the "hot 3". I paid up and he shipped it. I did not bother to ask anyone because I knew the answer, it would kill my transmission like a silver bullet. I hooked it up, i t ran great, but slipped in so many situations that it was not really even useable. I did a run from 0-120 MPH and stopped pretty hard, shot the transmission pan with an infrared temp gun, it was 280* in the pan after I stopped. I took the PE off and experimented with some other light fueling boxes. None worked like the VA so I ended up buying another VA and sticking with it.
At about 80K miles I saw a Torqus Maximus advertised for sale. The price was good and my curiosity got the best of me. I paid up and put it on. Subtle but VERY nice difference. Ran awfully good... .
At about 90K miles I wanted more power again, but decided to try to get it a little higher in the RPM band and a little smoother. I traded off my DD1's for a set of DD3's. Dropped them in and was amazed again. Slipping was not as bad as with the PE, bu still bad. Cruise control was unuseable on all but dead flat roads with the surging. 600 RPM of slippage in OD was available to me any time I wanted to see it. BOY HOWDY, it sure runs nice though, should be about 350HP at the wheels, maybe more... ...
At about 120K miles, yes the same stock turd that won't make it a week without upgrades lasted 120K miles, I started to really get nervous about a possible failure. With my job I could end up 400 miles from home by the end of the day, and 1000 miles a week is not too uncommon. The harping on the TDR about them dying in piles of molten nastiness was getting to me. I found a shop/guy I wanted to do business with that wanted a price I could afford to do the job so I signed up.
During the autopsy of the trans I expected carnage and wreckage, but none was apparent . Did I mention that the ONLY fluid and filter change was at 40K miles or so? Yep, it was done ONCE in 125K miles. The fluid looked like used motor oil mixed with a purple pearlescent paint. The magnet was 3/8" thick with crap if it was a milimeter. There had to be something somewhere hosed up for that much ferrous and enough aluminum in the fluid to make it look like pearl paint. Any guesses on what it was? The LAST thing it should have been. The low/reverse planetary carrier had been eaten by the annulus/shim. It was a FULL 1/8" deep where the two had eaten each other up. The source of all the metal was found, but it should not have been unless there was a lube flow failure at some time. Evidently a port or passage had been clogged although none were clogged at rebuild time. The clutches and steels were all normal to low wear. End plays were normal on all but the gear set that was eaten up.
Bottom line? The trans would likely have gone a good while with ME driving it the way I drive. It more than likely would have made 150K easily, and probably farther. Did I waste money upgrading? No not at all. The peace of mind when I pull out of the driveway with 400+ miles ahead of me is worth it alone, add to that the fact that it works a world better and I am quite satisfied.
Why did I type all of this? LOTS and LOTS more of you guys are way out there when auto trannies are involved. They are NOT the weak miserable POS that they are made out to be. There are some stock units that are destined for death, but they are very few and far between. The majority of them are dead solid and last just fine. What we have is a darn good trans behind a super engine and VERY few guys that know how to operate the two together. Add about 100HP to that and the guys that know how to keep things happy are even fewer. Lots of guys hurt trannies because they did not know when it was vulnerable and when it was strongest. The stock trans capacity for power is USER determined. There is NO number, no mod level or combination or anything else that is going to determine when and where the trans is in danger. The way it is used is THE key factor in the life of a trans regardless of power level.
I hope like heck someone gets something of use out of this, my fingers are all tuckered out now
Attention: TDR Forum Junkies 
Maybe I just got lucky. But I just though I would add mt 2 cents worth. 
