These air vents from Upstream Outfitters increase flow by about 50% or so just based on my being able to actually feel air stirring and blowing on me. The cost is about a third of the erPods and maintain the original OEM look.

In the picture below, only 3 thin structural pieces radiate out from the center. The entire duct opening is no longer restricted except for the outer stainless steel vent cover.

The only slightly annoying part is deconstructing the OEM vent cover (drilling out the rivet and persuading the 3 pieces to separate). After doing a few, I found that inserting the pointy ends of needle-nosed pliers toward and around the rivet while prying apart the pieces seemed to make the job easier.

Finally, if I was to do this again, I would save $15 each and not get the damper version, since I never found a need to use the camper . If air is blowing on me, I just turn the vent to point it in another direction.