Not to clutter your thread up too much, but would one advantage of the external snorkel be to grab "cleaner" air on dusty trails? Would the hidden snorkel have more chance of dust ingress than an external? I ask because I run trails that get incredibly dusty during the dry months, but worry that an external snorkel would snag on limbs and other tight spots.
In theory, I would say yes, external snorkels could grab cleaner air...if you're not following someone kicking up dust.
I was able to keep "most" of the wheel liner so dust ingress is no worse than stock. When I pulled the fender panel to install the snorkel, there was hardly any dust past the liner under the fender after over countless desert, snow, and mud trips. Not to mention that my airbox was relatively clean.
With that in mind, I don't think the chances are greater to ingest dust with a hidden snorkel with a wheel liner vs external snorkel. I believe it would be a different story if there was no fender liner.
If that were the case (no wheel liner), I most definitely would have routed the hidden snorkel into the cowling, like most who have done this mod, to keep as much dust out as possible.