I've been using a Gen-Turi for a number of years and it works well. I had to saw off part of the existing generator exhaust when attaching the horizontal piece of pipe to keep the protusion length about the same. We also have the generator exhaust next to a slideout and do not attach the Gen-turi if doing a generator run of a half hour or less.
I cannot do a permanent mount of places to hook the Gen-turi since one point is on the side of the slideout when it is open. I tried the glass lifting type suction cups but they only stay on for a few hours. I have ended up leaning the unit against the side view mirror and that is good enough.
No motorhome is airtight. There is always some air leakage.