I think it really depends on the breed. But I do like feathering. Sometimes when there is just a little bit of straggly feathering I think it looks best to just clip it. But if the horse has nice, full feathery feet (and they are well maintained) I think it's best to keep them. Not all horses are able to grow such full feathers, it makes them stand out. If you are not showing in anything that requires you to clip them, then keep them. It help protect their hoofs from moister anyway.
Depends on the breed...Drafts should stay with feathers for sure. I have both, some with and some without. But the ones with are because i"m too lazy to totally clip them...And I hate fighting with the clippers.
I don't like fuzzy heads, so I shave the mini's heads and on the big horses shave the whiskers and trim the underside of the head. But other than that and a bridle path, I like them natural... LOVE feathers, no matter how much they have ;)
At my barn, we don't clip or trim anything on the horses- I think it isn't good to change the way a horse looks just because we like it better. I really like the feathers and long hairs on horses. That is what they were born with and that is the way they should stay.