I'll join in as another satisfied Vortex fan user! I really enjoyed the simple "retrofit" install, not requiring me to break the roof seal and remove the existing roof vent like the Fantastic does. I put an inexpensive $10 Camco vent cover over the outside of mine, keeps the rain and bugs out.
I haven't gotten around to it, but I did pick up a PWM + reverse gizmo from Amazon, to replace the built in resistors that come with the Vortex.
The fine mesh screen covering the blades clogs pretty quickly for me, mostly because I run it while cooking, and I think it's grease/smoke that's getting filtered on that screen. Soaking it for a while in some hot water + Dawn works.