I bet it would be hard to let him go :(
I understand the reason you may have to completely though..
I would actually have to know his personality to decide completely.
How he moves, temperment, build.
I actually agree with you though.
You obviously know him better.
I actually like to show my horses, and also have them as my riding horse.
Just my opinion (not trying to start an arguement by no means)
I'm not a big fan of stalling my horse, and only seeing him on show days.
I mean the horse sees the trailer-show-trailer-stall.
I like doing all sorts of things with my horses not just one thing.