I may about 48 if some fall into my lap (basic ones) but generally I only slot IO's after I'm really done with the character (about the same time I start getting them incarnates) by that stage I consider the character done, and the set's and incarnate stuff is just something to keep the character played a little.
I don't EVER build for Uber, I always build for concept, Grey Wanderer my WS is a terrible awful WS build, but he is probably the single most fun character I've ever played (though I could be biased, I did meet my wife playing him 😄 )