Would highly recommend the Fox Transfer as it works very well and has been put through the wringer. (Most of these remotes can be paired with matchmaker clamps you can purchase that allow you to attach both the shifter and dropper remote). I’m not a fan of the Reverb. I just picked up the Cascade (as Jeff recommended) for my XC bike because I’ve heard good things.
A follow-up to my initial post about an externally routed dropper post. I bought the PNW Cascade and have used it for about 5 out of the last 7 days. So far, so good. Installation was pretty simple and it works pretty smoothly. Thanks for the recommendation Mr. Barber.