Michael Harrison has asked the following question.
'I was wondering if you use kadee couplers fixed to the chassis instead of the standard type? What about bogie wagons? Do you use kadee couplers fixed to the bogie or wagon body or the standard type fixed to the bogies?'
The answer is' yes, I've used both couplers in both positions'.
On block trains that run together I've used rapido couplers in a fixed position with the corners cut on a diagonal to negotiate corners. This is a godsend for long days at an exhibition where you can just let the trains run without having to worry about the inevitable 'uncoupling in a spot that you don't see until the wagons are piling up on the floor'. On each end of these sets we would have Microtrains couplers, as well as on the loco's. However while this works well for mainline trains which never stop, if you should be predisposed to a bit of shunting, then Microtrains couplers on every wagon would be a good idea.
Couplers on long bogie wagons is another matter entirely. The general leaning amongst the brains trust is that bogie mounted couplers are a much better bet in terms of 'runability' vs the body mounted couplers. Just to confirm this ( to myself as much as you dear readers), I've just checked this out tonight.
First up is an Nc coupled to a 50' Z wagon on a 15" curve. I was surprised how little
offset there was, and theres probably not that much difference between the 2 options.

Surprised by this, and being a good scientist, I then checked the coupling geometry with 2 50' Z wagons. While the center of the curve is OK the entry point to the curve is a different matter entirely. The offset is quite large and frankly just asking for trouble.

so, you can be prototypical, or you can run trains.
To those who say, why can't we do both, the answer is either A)simple physics, or B) we could but we want a life as well thanks very much. Oh and a layout with more than 3 wagons on it.