i use a mouse on my desktop, and trackpad on laptop.
Both have advantages, mouse is way easier to traverse large spaces accuratly, but requires a flat surface of ideal material, whilst a trackpad doesnt require anything.
Personally, if i had a large trackpad that i could use well i would use it for my desktop.
such as an Optimus Tactus, that would be great because i could remove my mouse entirely and use it as a trackpad and keyboard combination, or even better just use a BCI.