Didn't read all the posts in this thread, so forgive me if it's already been said ...
For me, I have two sets of criteria for a "platform" ... use and sport.
For sport, I have a variety simply because I want to have a well rounded knowledge of how they work and perform.
For use, I stay with one or two "platforms" so that when the need arises, I'm not searching for a magic button to make the thing go bang.
And we "train" with the weapons routinely just to make sure we can react appropriately.