When I ordered my 2XL and 4XL/Elite I ordered with "slide remotes" also and never used them. These are still NIB with the "clear seals" on box top intact and the "bar-code seal" still intact on the other end. eBay sales look interesting for used - I'd sell these for $85 shipped if that sounds reasonable. I'd rather not do the eBay thing.
I've an N adapter that was used for 20 minutes for a diagnostic test that TiVo wanted to do when my Elite started showing a MOCA connection and it's been Ethernet connected always. The N adapter works but didn't "trick" the Elite into seeing something other than the MOCA connection. $60 shipped in the box.