I havent played it much so I cant give you my opinion on whether its good or not. But I am pretty sure (not 100%) that you can use the gamepad for it, at least you could for the psx, but its bad for when you have to press up and down or left and right at the same time. You can also buy the little dance pad for your fingers as another option . It seems to be a VERY popular game so it cant be too bad lol.
I never played the first version, but I liked the 2nd Mix. I still have it for my Dreamcast. You can play it with the gamepad, but it will test your coordination when you start getting multiple key presses within beats of each other and your fingers get all mixed up.