There are several aspects of couplers and most of these have
been discussed in the previous posts:
Appearance, coupling distance, reliability, size, size of draft
gear box, whether or not they have a magnetic pin, how strong
they are, how well the train stays together during operation, etc.
If my memory serves me correctly in the following of this thread
no one has mentioned the topic of "interoperability". If you are
building a contest/shelf model you don't care. If you have a layout
where all the freight cars are "controlled" and you -can- all have
the same couplers on them then you don't care. If you don't do
any ... or very much ... switching then you don't care as much. But
if you are talking about a layout that has lots of different guys
bringing their equipment to operate then you care - a LOT.
On layouts where lots of people are contributing the current
"standard" coupler is the Kadee #5. Simply because that is what is
on most of the cars in most of the train cases. Not necessarily what
we might like to admit but it is "the truth".
So my point is that if a new coupler is going to be accepted ...
rapidly ... it needs to operate well with the #5.
And, regrettably, none of the "better" couplers we have out now
operates as well with the #5 as they should. That's probably due to
a design aspect of the #5 (that little 'lip' on the very end of the
face?). But the bottom line is that if a new coupler doesn't play
well with the existing #5 then its acceptance is going to be slower
than it would if it did - considerably.
BTW - the #58s and #78s don't seem to couple and uncouple with
each other as well as the number 5's do either! They're "acceptable"
but they aren't as reliable as the #5's when using an uncoupling
ramp -and- they take quite a bit longer to uncouple using a pick.
- Jim ... dreaming of an HO car with operational cut levers
that 'interfaces' with the #5 ... I've always been
a -big- dreamer ... but I still have a large supply
of #5s and continue to install them on all but a