I have to admit that I'm quite happy with the Properties Palette. During a period of time that I can't claim to have been part of or witness thereof I was a bit less happy with it. I no longer find myself closing it accidentally and like the ready access to information. I have settled on putting it over at the right side of the UI, like this.
What about you? Anyone like it stacked above the Project Browser? I just didn't like them both getting squashed. For Revit MEP it does compete with the default location of the System Browser, which I prefer at the bottom of the UI. Since most of my work involves people using the stock deployment I don't spend much time customizing my UI or setup because that puts me in a different environment than the students. I do prefer the "light" style over the "dark". I also prefer the QAT below the ribbon so I can see more of the title bar.
Speaking of students and different environments, one item that proves a bit confusing at times is the way the UI squashes panels and tools on the ribbon when the resolution is coarser than fine. This means that my projected screen often has a slightly different presentation than the student computers...leading to confusion when telling them to click here or there...etc. Fun fun!