House windows aren't like car windows. House windows have trapped argon gas, so when you install tint, unless you're absolutely sure on your window type, gas, glass type, panes, then you might trap heat IN the window which will make it expand. Expanded seals on double pane windows will break the seal and your windows will basically be good for shit at that point.
My windows are all semi-polarized. A mild privacy mirror, but it's only effective beyond 15 feet or so. I forgot which VLT, but it's not that dark. However, the tint is built into the window because that stuff off the shelf will eventually get scratched up. IMO a worthwhile investment over triple pane windows, although IIRC, triple pane blocks slightly more heat than tint, unless you go with a 15-20%(which isn't that dark if you get a silver tone).
So basically, find out what kind of windows you have, then figure out if you want a copper, silver, titanium, or color toned windows. Watch some youtube videos or whatever you need to get the confidence to do the job. It's very easy, just take your time, you're not some competition speed installer(some of those guys wind up with jobs that bubble after a few months, and they simply don't care).
