Oh yeah, Kadees... I know what you mean. Did three pairs of log buggies and a little logging caboose...
...which meant assembling fourteen #15 couplers.
DOING!
(ok... now where did the damn spring go this time?)
I do really like Kadee's consistent quality, and use their metal trucks and #148 couplers on everything that needs upgrading. The #148's are an easy to install alternative to #5's... and don't go doing! on you.
Looking forward to seeing whatever else you come up with for your train.
Those little springs are so much fun, I did find a way a little easier was to use a little ac glue on the botton of the spring and it would stay put so you can place the other side of the retainer plate.