Had an opportunity to try out the Hopkins wiring harness...wrapping up the install this weekend. I have the Curt 13558 receiver and found a few sites saying the Hopkins 46365 harness was compatible. I used eTrailer's DIY videos as a guide. I'm down to the last step running the power wire from the trunk to the battery box via underbelly. This is the only step I'm not super thrilled about as I don't like running a power lead outside the car. Everything else was relatively straight forward though.
The price difference is small at the end of the day ($45 vs $100), but I wanted to test it out (and throw the extra $$$ at a plenum spacer)