I guess my main problem with the pre-98 trans would be the accumulators and springs being crappy and the friction material.
There are a few other parts that were updated for a reason in the 98 but Bill, I don't recall you ever removing your valve body and doing the J-Mod on your car. If you haven't, that would be one of the cheapest mods you could do to your car and you would then have that 2nd gear, 3rd gear that would be way better than the 97 you had. It's a mod that should have already been done anyway considering the HP you're now putting out but I just don't ever remember you having it done or doing it. Maybe I missed it if you did.
Another part that was updated in 98 was the little shaft that connects to the forward clutch cylinder. The shaft with the taper is much stronger than the shaft with the groove. The shaft with the groove tends to break at the groove.
Now, accumulators side by side.
Instead of the little thin o-rings on the older accumulators, now the seals are rubber bonded to the steel part and giving you a hell of a lot more seal. I also think there was a spring difference too because the earlier years were breaking. The springs I bought from Ford were purple and blue and he said they were the stronger updated style. (Just going by what the parts dept. guy said on that one.)
After digging into a 93 and a 94 trans and doing a J-Mod to a 98 and swapping internal electrical parts from the 93 and 94 over to the 98 so that it would work with my 94, I just prefer the 98 trans. It's simply better in many ways. Yes, there are some of us, including me that have a 93-97 trans that is giving no problems at all at the moment but when it starts, it's over with. When mine starts, if it ever does and I'm sure it will, I would not even consider a rebuild of my current trans. I would just do the 98 swap again. Cheaper, easier and I know I'm getting the updated parts and not reman'd old parts.
Bottom line, I suppose that if a pre-98 trans is well maintained and not dogged out or abused much will last many many miles but if it ever starts the shudder, you can just about bet that the end is about to come for that trans.
Headlights... 97 and 98 are bigger and obviously they do put out more lumens but honestly I have no problems with mine but again, they are new housings and not re-chromed or polished. I also have HID's in the bright and low beams and both can work together. (could be the reason they are kinda illegal) An HID being inside the halogen housing can omit some very bright light. You can ask Jamie about this issue. He has had more experience with this than anyone on here that I know of and he'll tell you himself that he would rather have a halogen housing with HID's instead of HID's in a HID housing. I pull up to new cars on the road that have HID's with HID housings (not Mark VIII's) and here I am with my little halogen housings and 10,000K bulbs and my lights output is over powering them. I see mine over theirs and if I put mine on bright, it's almost like the sun is out. I think they should conduct a lumen test with the Gen 1 Mark VIII halogen housings with HID's installed compared to Gen 2 Housings and see which is greater. All I know is that I am putting out some light and knock on wood, my POS gen 1 trans is still doing good and hasn't given me a problem yet but Jamie did the 1-2 and I think the 2-3 accumulator and spring upgrade and fresh Mercon V and filter change. I know in the back of my mind that I have a POS TC and it's day is coming. I bought the car last February from him and I doubt I have even put 4K to 5K miles on it during the 10 months I have owned it. I don't believe the $2000 I paid was a bad deal.