Tony:

I stopped using a tubeless peep about 6 mos. into shooting a bow. I don't see the need for one. I WAS having some issues with my D-loop twisting....but I ordered some BCY loop material and actually tied my first D-loop on, Friday night (Shot my best 3D round ever, Sunday.....with my loop and arrow that I fletched).

As long as your D-loop is snug.....and you have it aligned with your peep (and I'm assuming your string has 100 shots or so on it....and it's "trained" itself....or "settled in")....you shouldn't ever have an issue.

Good luck.