For things that don't require visual precision, such as music production or writing or concept diagramming, the iPad is highly capable. I look forward to the day its touchscreen can handle pen input to an equal degree.
I was free to choose any of these, but I chose to use an iPad because it allows the immediacy of sketching and painting with natural media and the significantly faster turnaround of digital image making.
Like any tool it takes some adjustment, but once it clicks, there is nothing more immediate than using your finger(s) to directly paint an image. The fat touch region is a non-issue once you've learned to use it - after all, there's nothing terribly immediate about flexing one's fingers and having a mark appear 2-10 cm away at the tip of a pencil, pen, or brush - we've just become so accustomed to it that it seems "normal." A bit of time with an iPad and tablet finger painting seems equally immediate and natural.