Same here. I originally switched from a 3M clear to Oracal 3651 because, at the time,
we were applying a print, then diffuser, and then another print for our backlit signs.
The 3M was too thin it would stretch when we applied the second print & get out of register.
The Oracal is thicker and more stable and I haven't had any issues with it, so haven't seen a reason to change
even though we no longer have to double layer.