I first used a Kadee Whisker coupler about 2 years ago. I never looked back and you wont either.
I buy the bulk packs of #148s, Kadee #14s...Now that is all that is all that is on my trains unless they come with Proto-Max as they are nearly identical to the #5/whisker/kadee.
The only thing I can fault kadee couplers for is that sometimes the little spring comes loose in the package for the couplers. To put that back on, youve got to have some patience, good eyesight (or some jeweler lenses), a steady hand, and a confined space so that if it springs off it doesnt go flying into oblivion.