I'd suggest that you establish which height works for you, and stick with that. If you intend to cut or remove the Kadee, your concerns about whether the coupling is drooping is purely academic: Your intention is to replace the coupling.
I've been running a shunting plank for a number years, and all fitting a selection of Kadees. These run from No.5, to No.19. Once you follow the basics, they run very well. Naturally, there are variations, but knuckle height is important. As we all know, the operation of the layout is only as good as the constituent parts.
If you want to enjoy Kadee, try using the web pages. There is a lot of information on the site.
Some UK-ish modellers don't like Kadees: I can understand that. They run clear across any aesthetic notion you have of British models. I'd respectfully suggest that the cornerstone of 'cutting off the coupling' is rooted in it's alien origin. For my uses, the Kadee is just right.
Now, if I can find a Kadee/3-link combination, I'm in.
I don't have any connection with Kadee, and I've never met them. I need the coupling to do an exacting job, and it works.
Happy modelling Peeps!
There isn't an automatic coupling made that looks good, the best you can hope for is unobtrusive and the master at that is the Alex Jackson. They are excellent if you model in P4 but just don't work in OO. The slack in the rail/wheel interface allows stock to waddle so the couplers don't line up accurately enough to couple reliably. (Voice of experience, I tried them many years ago, despite having that spelled out to me. 20-something me thought he knew better!).
The Kadee, possibly uniquely, is at least based on real railway practice, even if it's not been UK railway practice until quite recently. Presumably, if foreign railways didn't use knuckle couplers, there'd be no objection.........
I've been using Kadees for 25+ years and consider their overall combination of functionality, reliability and (once you get the hang of it) ease of fitment to the vast majority of models is beyond equal for OO. They aren't quite "fit and forget" but if you get the fitting bit right, and your layout room/shed doesn't suffer from damp, they get pretty darn close to it. The real godsend is being able to effortlessly separate vehicles simply by lifting as in the old days of the Peco Simplex/Hornby Dublo couplers, neither of which I ever recall being referred to as un-British in appearance. . Kadees don't look radically different from those but are smaller (a lot smaller in the case of the plastic HD coupler).
I also fit and maintain Sprat & Winkles as part of my involvement in a layout with an awful lot of stock. I've no complaints whatever about their performance and they are fairly invisible so long as one fits goalposts rather than a hideous wire stuck or soldered across the buffers. However, they are MUCH more labour-intensive than Kadees. In essence, S&Ws are upside-down tension locks with all the aggro that entails in the fiddle yard, followed by regular gauging/adjustment necessitated by (even fairly gentle) handling.
The slightly irritating thing is that the layout has few viewpoints closer than about 30" from the trains and you really have to squint to see if the stock being observed has 3-links, S&Ws, Kadees, or even small-head TLCs.
Edited by Dunsignalling, 15 October 2017 - 07:28 .