I'm wanting to do a small shelf layout around a spare room walls.. and I used to do this hobby years ago.. I remember getting and switching all my cars to kadee?? or something like it.. it had the sprung knuckle couplers and some cars had these right on there to begin with, which brand was that? or what is the hottest/best coupler these days anyway.
Kadee is still the best. There are other alternatives out there that some may chime in on, but I would consider them in the niche category.
What era and railroad are you intending to model? Kadee does produce cars that have kadee trucks and couplers pre-installed but only for the transition era. The new Proto 2000 and walthers cars now come with a kadee clone, metal coupler with bronze spring, that are almost entirely indistinguishable from the real kadees, and operate without any differences, they may as well be considered Kadees. Majority of modern rolling stock manufactures are balanced out in terms of operating quality. Bulk of what I saw back when I worked at the hobby shop now came with metal wheels and some form of knuckle coupler, usually McHenry or Bachmann Mark II couplers. These are plastic clones, which are suitable for switching layouts so long as you equip everything with them. Mixing coupler brands always results in disappointment. With slow speeds and very short trains, the plastics work great, and the scale McHenrys Look terrific. However the old plastics that used a plastic tab to spring the coupler back? Don't even give them a second chance, never heard of anyone besides the christmas only guys who had success with them. Atlas and Accurail ship their cars with accumate couplers, which are a bit oversized, and will work fine when used in an accumate only fleet, but they do not play well with others, particularly with switching. Swapping the couplers to Kadees or whatever brand you are using is a good viable option. In all honesty, take a look into what era and region your going to model and compile a list of rolling stock your going to need, then just buy from whatever manufacture makes said item, its going to difficult to assemble a fleet with much variety sticking to one company.
