Yep, in 2 1/2 years of fulltime we have broken a couple of the plastic round things and had to replace them.
Never broken a string but have had to tighten a couple of them up.
I see on the new Pinnacles they are using the dual roller shade system in place of the pleated type window shade, one is a blackout shade, one is a mesh shade. You can use either or both with the blackout part of the way and the mesh all the way.
Do not know it they are going to do this on any other product lines.
Robert & Bale the "Traveling Dog"
2012 GMC 3500HD DRW