I use and highly recommend Kadee couplers. I experimented with Delton knuckle type
and found the Kadee's worked much better. I body mount all couplers when possible as
this makes for much improved operation, especially for switching and backing up. I recently
backed a 16 car train (about 22' long) up a 3.5% grade through switches and around curves.
You can't do that with talgo (truck mounted) couplers. If you want a smaller coupler you can
use the gauge 1 coupler of Kadee's and they will mate with the G coupler, however, they do not
uncouple with the magnet when mixed with the G coupler. The #789 coupler works for body mounting
on most cars. Kadee is coming out with a new coupler like the #789, but with an offset knuckle.
Contrary to Kadee's statement, "these couplers are for larger radius curves",
these couplers will work easily on 4' radius curves and on most cars will work down to 2'
radius. On the smaller radius their delayed uncoupling action may not work. The main criteria
on radius overhang from the truck pivot, the shorter this is the smaller radius you can use.