I couldn't agree more. It's fun watching Netflix on my ipad, or being able to use safari to do light browsing with limited interaction.
But when I need to actually do more than type at snails pace I hit the desktop. Video/sound editing, typing papers, remote support, and browsing is so much more comfortable with big monitors, core i7 980, 12 gig ram and 6 terabytes of hard disc space.
During Hurricane Sandy power outages, I was able to do work on my desktop hooked to the generator(albeit without internet), while the ol' ipad was dead due to the issues in the area.