With you there Yogi. Far less complicated and there is this sort of myth that if you convert somehow the truck won't start anymore? It starts no differently at all. One touch of the key and it's running. There is less current going through the starter contacts for one thing, they aren't any bigger on the 24v unit. Less cables, only one battery to have to replace. More space under the bonnet for other equipment. There isn't a down side to converting. OK you may not want to, but don't say the 80 is less reliable for doing it. These are old vehicles and whilst well made with good components, just how much longer will things like the changeover relay last? Mine was certainly showing signs of burning on one of the terminals.
It doesn't get cold here in the UK, but mine started first flick after being stood for a week when it was -5 in that last snow we had. I know because I went outside to try it on purpose. Not many people do this conversion so it's wrong to suggest that it's some sort of widespread practice.
When you build a vehicle for special purposes like this you tend to add all sorts of extra electrical kit. That means there is always the potential for introducing some kind of parasitic drain. With the cranking battery isolated and all vehicle power coming from the other battery, you should never end up with a flat battery for starting. If I do, then I have put two Optima batteries in (one up front and one in the back) which have universal posts meaning that I can drop a spare battery into the cranking slot. With the 24v start, you need to have two decent batteries to start the engine. If one is down for some reason then the system really knows about it and cranking speed is poor. OK I hear the arguments about cold battery loss and at minus 60 degrees etc etc, but I am not planning to cross the Arctic circle any time soon so it's not really an issue for me. Plus I can connect the two in 12v parallel from the vehicle cabin. Just like the starting system on the Colorado - 2 batteries but not 24v. I have fitted decent batteries and if I ever have to crank the engine more than say 2 second, I know there is something seriously wrong.
Unless you know the reason WHY the 24v start system was fitted then you can't necessarily say the 24v is somehow better because it came like that. Like Yogi said, most of the world got one battery. And no diff locks! Mr T didn't fit diff locks for a reason therefore all diff locks are bad? Err hang on ....
If you want to run standard tyres fine. If you want to leave the third row of seats in, fine. If you like the dim headlights, fine. If you don't want to fit a 3" stainless exhaust fine. If you like tinted windows, fine. If you want a roof tent, go ahead. It's all fine. Do what you like. No one is making anyone convert.