I did it with a Gen 2, it was easy to jailbrake. That being said, I use the jailbroken features very little (it is just a music machine for the car now). It is like the days of old satellite dishes, if you know where to point the dish to find what you are looking for you can find almost anything, but it takes a while to figure out where to look. You can get apps for free and apps that are not in the itunes store (opens up many possibilities for new apps as apple is very controlling). I've never tried to get music directly on my ipod, so I have no idea if jailbreaking makes this easier.
If I jailbroke an iphone, I would find it much more useful (it's always with me, it has a mic built in, it always has access to the internet to grab new apps etc.).