While I always start my designing the old fashioned way, with a pen in a sketchbook, the finish work is done at a computer. My machine of choice is an Apple. I don't want to think about my tools but rather just use them while I think about my work and have has better success on Macs. I also use a Wacom digital drawing tablet for my drawing. Because I have drawn for so many decades, muscle memory allows me to draw on a tablet while looking at a screen without effort. I've owned the Wacom Cintique screened drawing tablet but didn't care for it.
My setup in my design studio is a 27" iMac with a medium sized Intros Pro drawing tablet. A keyboard, mouse and trackpad are also handy as well.
In the house or on the road I rely on a 15" Macbook Pro with a smaller (and lighter) medium size Intuos Pen and Touch drawing tablet. The tablet works via USB or wireless if I wish.
The key to getting used to a drawing tablet is to give your mouse to someone you trust for at least three days. Tell them NOT to give it back to you no matter how much you beg. After three or four days you will love the drawing tablet.