Yes I've seen what passes for home construction nowdays and you're description it quite accurate; I'd fire anyone I even so much as suspected had work habits like those. I suspect that may be part of the reason you've seen these fail; hacks, careless and no talent installers will do in the best of any product. I've had solartubes in two different stick built homes, one modular and a manufactured house. Not so much as a hint of a leak nor any condensation like you mention and this in one of the wettest locations in the country; the Pacific Northwest. My real question is whether or not they can be installed in the thin ceiling of an RV, still haven't found any 411 on that issue. I think that may prove a difficulty.