I've installed several of the units you describe. I use them on the front and rear windows because they're so cheap, lightweight and easy to install. They are capable of putting more force on the window that I could by hand. I know this because in the winter I could never roll the windows down in my daytona by hand, but a set of those power conversions could. They are no louder or quieter than any other stock oem power windows. The ONLY downside to them is you have to put a plastic cap over the hole in your door panel where your window crank was. The kits supply caps with a variety of depths to fit your needs. Paint them to match and they're barely noticeable. You can wire the window motors up to their supplied switches or up to a set of stock type power window switches, I've done both. I'll be putting a set of them in my satellite this spring and my brother wants a set for his charger.
You can get comparable ones on ebay for WAY cheaper than on electric life's website. Like a kit for all 4 windows for around 100 bucks.