I tried Tow n Sees when we had an SOB. They both eventually fell off. I didn't always clean the mirror and suction cup with windex before mounting them.
I bought Brian's McKesh mirrors on the forum classifieds and have since sold them.
I sold them for what I had paid for them.
I didn't have problems with scratches, but had trouble keeping them adjusted.
I finally bought a pair of replacement extendable mirrors for the Suburban on Ebay. These don't have the lit turn signals but the do extend and adjust with the remote control. They were about $220 on Ebay.
So far these seem to be working for us. Here's a picture of them. The small lower
mirror on each side is a wide angle.