Hello! I am converting a Promaster and I have heard over and over the importance of a good roof vent. It seems like a Maxx Air is a good system but I was wondering if anyone has a Dometic Heki 2 De Luxe with the venting feature. Does this work as a good alternative to a more traditional vent? I assume the hatch must be open to vent. Is this a problem? I have thought about installing both the Maxx Air and the Heki. Would this be overkill? Any opinions on the Heki 2 would be helpful as user reviews seem scarce.