All good points, however here on the west coast it is very difficult to find anyone who will use butyl so there is that. I have had some installed and I have installed some; first off its a 2 person job no matter what, however it is not super difficult, just have to be careful and be calculated in how you proceed. I highly recommend taping the crap out of your window channels, meaning taping around where the windows go in, tape it back aways, probably 6" or so. Even use some masking paper to protect the paint because the buytl or urethane tends to get everywhere.