Back in 2010 my parents asked me wether I wanted a graphic tablet or an iPad and I have chosen my Wacom- best decision ever. I have used iPad - not with a pressure sensitive stylus, but still. If you want to produce higher quality art and develop more in general- I'd recommend Intuos, for it's size, it's precizion and range of customizable options.
I can't really say, since I haven't used an iPad or direct-touch tablet like Cintiq, but I can vouch for the Intuos and say that, especially once you get used to it, it's very easy to use. I really don't have many complaints about not looking directly at what I'm drawing on.