I have one in my WRX and most recent cars I've owned. I open the one in the WRX every chance I get, and the shade is pretty much always retracted. They are pretty much a requirement now that I've had them.
However, after driving/sitting in 4Runners with and without when we made our purchase last summer, I was really surprised by how much headroom the sunroof ate up in the 4Runner. The back seats felt especially claustrophobic with the sunroof. For roughly the same price, I convinced my wife that a TRD ORP without rather than an SR5P with was the way to go. Three months later she learned the value of the locking diff while she was driving exiting a steep wash on a tough trail in Utah and she now appreciates the trade off. I do miss having the sun roof on warm days, but lowering the rear hatch glass somewhat makes up for it.