I don't have an iPod, but I do have an HP Touchpad running Cynogenmod.
I also have a desktop and two laptops that are all used on a consistent basis.
There are things that I can't do on my Touchpad as easily as I could on my laptop. This includes word documents, excel, photo and video editing, etc... even with my bluetooth keyboard.
Also there are some things that I don't want to do on my laptops that I do on my desktop, especially when there's something that takes a bit of processing power, I don't want my 100 degree laptop on my lap when I can have my desktop being blown off by 5 fans and staying cool.
I also have one laptop that is loaded with school crap and another that I just keep photos videos on.
Now that may be more than you were looking for, but the point being is that they all have their purposes and they all do better at some things compared to others.