For sport or range, the isosceles provides the best balance and less strain on the body.
But otherwise, knowing all of them can be useful.
Best to practice everything - weaver, modified weaver, reverse weaver, isosceles, one handed (either hand), prone, under, over and around cover, chicken wing, 'etc.
No telling which one would be needed, depending on the situation.
It will take lots of practice to be able to smoothly go from one to another, but really good shootists know them all.