I'm not going to disagree with your general post; I've never used Maya for one, and frankly, your rundown seemed pretty fair. I just wanted to see if I could help you with the shader ball issue. It takes some getting use to, but I actually think XSI's texturing method is more intuitive if approached with the right frame of mind.
It's funny how being used to something makes it seem "normal." If you think about it, there is nothing particularly intuitive about looking at a sphere with your texture on it. It doesn't look a thing like the alien/dinosaur/robot/naked female, or whatever you are modeling. In XSI, the render window lets you preview your material on the actual object. If you are tweaking materials that must interact properly with your lighting (e.g. anisiotropic materials, or transparent materials) it makes the process immensly faster, since you see how, say, the background refracts through the wine bottle you are texturing, or even how a caustic effect looks with a certain setting.
Granted, this is more interactive with a really fast machine, but then I do most of my work on a dual 600mhz myself, so it should ok for most professionals on an NT or Linux box (I like SGIs, but I really have no idea what the interactiviy of the render region is like on an Octane).
So anyway, try working with just the camera view and render tree view open, which gives you lots of space, and make liberal use of the render region (basically, leave it on during the whole texturing process), and you shouldn't feel blind for long.
Scott
