I've never used the Simple tab, either, but Poser 5 was when I got really into Poser. I had Poser 4/Pro, but didn't know enough back then to get much into changing textures. So the Advanced tab is what I'm used to.

I can see why people might prefer the Simple tab, though. Poser shaders can be crazy. IMO, the Poser Material Room isn't very user-friendly. With, say, Vue, you can poke around and figure things out. Poser has a much steeper learning curve.