We were always top of the bed until we went to Ireland a few years ago and I noticed the closure at the bottom, so we switched. All of our covers must have had the buttons in a placket so I never felt them or I it would have bugged me.

DS has a Serena and Lily duvet with HUGE toggle buttons, but when I put the buttons at the bottom the the Star on the comforter doesn't look right - two points at the top instead of one. It drives me crazy, but he doesn't seem to notice the buttons so leave them at the top because I can't stand looking at an upside down star!