stonefish, the flangless installation can be done well (I have had to put some in that way myself and have had one leak), the main issue I have is that it is a bit of a crapshoot getting it done right unless you are willing to watch the crew the alot while they are there. Alot of the crews I see out doing window replacement, I wouldn't let wash my driveway.

Oh yeah, get referrences and call them all, find out who the lead was on the job and if they did a good job request them on yours.