Orders of magnitude? I can believe your desktop is faster than a laptop, but 100x faster seems a stretch. Still, I think there are valid reasons for preferring a desktop. Besides it being faster, you can have bigger screens etc.
I never understood that line of thinking. I have an wireless keyboard and mouse hooked up to my MacBook. When I hook up my external monitor I now have two screens, giving me more dekstop area than a single desktop. I don't see why anyone would want a desktop unless they have serious horsepower requirements.