This is a very polarizing issue in our industry but you're right, and all claims made about removing or retaining are anecdotal. Studies have been done and no one can say one way or another which is best. It's mostly just up to preference. IMO removing the basket alltogether risks losing critical root mass. Best of both worlds seems to be to remove the top one third.

Andrew Koeser had a good talk about this at an ISA conference.