.....after shooting a few arrows, my dang string/peep would rotate almost 90 degrees and I'd have to keep pulling my D loop around to straighten it up. Shop told me that it's because of the factory string cables and this is common with "inexpensive factory strings".

Sound right.

Find a new Pro Shop. if you can twist your D-Loop there is a simple fix, tighten the D-Loop in the right location, issue over. Sounds like they just want to sell you an after market string and labor to install it. Sure there are strings a lot better than factory strings but factory strings can last a while and the peep sight made to index correctly.

Its common with any new strings. My winners choice done the same thing on my new Elite. All they have to do press it and put 1/2 twist in the string and it will straighten the peep out.

This!

Had a Mathews and Bowtech do the same thing. Had nothing to do with the D-Loop.

I call . All strings will have twist. They need to re-index your peep. Or do it your self. The D loop deal is like a band aide. It will help but not solve the issue.

^^^^ About says it all.

It's shops like this that made me buy a bow press.

And this is why I drive to Alvarado Archery!! I replaced my last string after 5yrs...shooting 75-100x a day i wore them out, and stretched out over 1/2" Vapor Trails my new choice

David's or Bargain Hunters?

Yes most strings will twist, yes you can buy aftermarket strings that won't. But at mentioned above, either twist the d-loop or put the bow in a press and give it a half turn. Won't affect the tuning.