Thanks for all of your input. The cost difference is just too much to go with the Superhitch, although no doubt it is a superior product. If I were hauling larger trailers I'd do it for sure.
I'm going to go with the Curt or Reese 2 1/2" receiver underneath the factory receiver. I have an old 2" extension that I will modify for use in the factory receiver and I'll tie the two receivers together similar to the superhitch, just for added peace of mind.
An RV dealer who installs extensions told me that sometimes extensions that are less sturdy than the superhitch can flex enough on bumps that trailer surge brakes can get the activate signal and cause your brakes to have momentary activations. Hopefully I can mitigate this by stiffending the Curt extension by connecting another extension in the factory receiver.
