So there's a 5 speed and now a 6 speed?
Piano - what do you not like about the 4 speed?
My 98 van with the 4R100 and 3.73's tows very well at 2500rpm in drive (od locked out) at around 62mph. My limited experience with a rental motorhome (2018) was that the RPM's at the same speed were similar, but in overdrive because of a lower rear end. The MH pulled starts and hills much better, I thought maybe just because of lower gearing as opposed to just having more gears.
I'm OK at 65mph, am in no rush in the hills, and honestly I'm not sure if i care whether I get 8mpg or 9... But I do really want reliability.
Totally agree with your list there j-d, I have no problem 'driving' the road and going with the flow of the terrain. I feel like the 4R100 is strong enough and probably not worth the extra $$ to go new enough to get the torqueshift. And if it did fail, I could get a strong rebuild for the cost difference of buying a few years older in the first place.
Condition is more important to me than age/mileage. Many of the ones I'm seeing in the 2003-5 range have around 80k miles which seems just about where I want to be. If maintained well, I'd be comfortable that something of that age would give me another 10 years of service. Seems like the E450 V10 motorhome chassis hit it's stride in 2001, I'm thinking anything past that is just refinement.