If you are serious about art, I would strongly recommend a Wacom tablet. From my personal experience as a gamer and an artist who learned the hard way, I started doing art with the mouse because I am very efficient with the keyboard and mouse. As an audio editor, you're always keyboard shortcutting your way to victory. Plus, getting all those headshots growing up actually seemed to be paying off. I had heard that tablets were the key but I thought all the art nerds with their tablets were just being snobby as usual.
However, my progress became logarithmic after a while. The problem with getting used to the mouse for art is that eventually you will want to learn the tablet because it offers pressure and stroke angle. Eventually you will cave in and find that it is a much more expressive input. When you finally do that, its like having to learn all over again. I would compare it to learning to play an instrument again. Sure you may be familiar with music already (the software), but the instrument (the tablet) will be foreign.
God is this so true. I obtained one recently and it felt so nasty....I honestly felt like I was a cripple doing art and I could not fathom how anybody would do it. I have siince pushed it off till I can obtain the 4k one that I desire. I feel that when I get the new 24HD Touch it will be more like actual drawing as the screen will act as my paper. I have become very skilled with a mouse... but I do realize that the strokes I have to take with a mouse could be done in 1/3 of the time by a simple stroke with a tablet pen. So, good advice here.
A Cintiq may be closer to drawing on paper, but still takes some getting used to.
There's the thickness between your screen and pen tip that gives a feeling of disconnect, a certain lag between drawing and having it appear on screen.
Changing brush sizes but drawing with the same tool never felt quite right either, and the peripheral itself is bulky and you'll have to adjust yourself to it.
Getting the hand-eye coordination of painting down on the tablet in my lap while watching the screen took some practice, but I think I might prefer it to the Cintiq's I had access to in school.