First, I wouldn't really call a pod hardware. More outboard software in a box.
There's a lot of different pods, I have the podX3.
One thing is that it can act as your soundcard, may or may not be useful.
With the x3 you get a plugin called pod farm, which gives you access to all the stomp boxes and amp sims etc in your daw. I suppose you get that with all the pods, not sure.
For processing mid range layers on a bass or reece it could be useful. The sound is very much guitarist driven obviuosly. If you pick it up cheap like Rev then why not.
Also it gives the option to record guitar, and has a XLR mic input (X3)