How good/bad are...

[TiVoPrince]

McHenry
upper/lower shelf HO couplers?  Especially interested in how well they perform in long (24+ car) trains...

[bnsf971]

I've replaced all of the ones I had with Kadees. They pull apart in longer trains.

[TiVoPrince]

Would 
the Sergent upper/lower shelf be a better choice?  Looking to properly equip my tank train with proper couplers...

[cv_acr]

Only if you replace EVERYTHING with Sergeants. Sergeants are not compatible with the standard Kadee-style knuckle couplers.

[bnsf971]

Sergeants are an "all or nothing" coupler. You can't mix them with other brands. They do look nice, and you'll rip the car in half before a sergeant coupler will uncouple.

[rswinnerton]

If you don't want to replace everything, go with Kadee. Avoid McHenry unless you like regular epic fails.

[Sokramiketes]

Sergents will couple with Kadee's #58 semi-scale coupler and its variants though.

[cv_acr]

Maybe, but they're really not designed to operate with each other.

The uncoupling function is very different. They might couple, but I'd be leery of how well they truly "play nice" together as they're really not designed to.

[Packer]

Your best bet for couplers are either Kadee, Proto-max (the newer metal ones), or Sergents. I haven't tried the Sergents, but the other two have yet to fail me.

On a side note, I have a few cars with the Mchenery couplers that have the metal springs. I haven't had an issue with the few cars that do have them yet. But then I'm running 30-40 car trains at the most on the club layout. Still they get replaced with the old standby (#5 kadee) when finances allow.

[cv_acr]

The Proto-Max seem to work OK, but to my eye they're heavier than a Kadee #5, and I've been going over to the smaller #58s. Once you get used to the #58s, the #5s look pretty overscale (which they are) and the ProtoMax couplers look absolutely massive.

[flight2000]

The Proto-Max seem to work OK, but to my eye they're heavier than a Kadee #5, and I've been going over to the smaller #58s. Once you get used to the #58s, the #5s look pretty overscale (which they are) and the ProtoMax couplers look absolutely massive.

Are the proto-max the same as the Accumates?  I've been replacing everything as quickly as possible with #58's, but I still have a few Atlas cars with those and my god it's David versus Goliath when an engine with #58's pick's them up from the yard.... 

I want to add the Sergeants to the front of my lead engines because they look really good.

Brian

[cv_acr]

Are the proto-max the same as the Accumates?  I've been replacing everything as quickly as possible with #58's, but I still have a few Atlas cars with those and my god it's David versus Goliath when an engine with #58's pick's them up from the yard.... 

No, the Accumates are 2-piece plastic couplers made by AccuRail. I hate them. The 2-piece split plastic head doesn't really work the same way as a Kadee/clone with a sprung knuckle.

The Proto-Max couplers are metal Kadee clones made by Walthers and included on their latest cars. They're pretty much a direct copy of a #5, although I feel like they're very slightly larger. And when you're converting other cars to #58/158s they look pretty clunky. But they seem to be a pretty fair equivalent to a standard #5.

I want to add the Sergeants to the front of my lead engines because they look really good.

Brian

I would reasonably expect either end of any of my locomotives to eventually be coupled to something, but if you run fixed sets always in the same direction and don't do switching with runarounds, this might work for you.

[TiVoPrince]

Since 
these will likely run exclusively on modular layouts.  The abrubt vertical transitions make #5 size couplers desirable as #58 tend to lose grip because track looks like SP in the 1980s deferred maintenance era.  The size differential is less important than uber-reliability in a coupler hostile environment. 

I will certainly apply a Sergent or KD#1019 to the last car carrying the FRED as the size difference is noticeable even at a casual glance, but the intermediates will get the larger couplers for increased reliability and compatibility...