Even a tablet that is not fancy and lacking the advanced features will give you much better control than a mouse. I find it still hard to draw directly freehand with my tablet without doing anything on paper before, I think that would need much more practice to become proficient, but the learning curve for using it to ink/color/rework a rough pencil sketch is not that steep. I think the difference (at least for me) is that when reworking something, even if it has lot of flaws, you have some guideline already on screen to orient your movements on, to deal with the disconnect of moving your hand on the tablet, but have the result on screen. I find doing things digitally is especially useful if my pencil sketch has problems, like for example with this picture Roy's arm was somewhat in the wrong place and the head wasn't right, and stuff just didn't work in my pencil sketch attempts at all, so I scanned one and rearranged parts until it looked somewhat right in broad terms and then drew the details over it in another layer, fixing things, and then rearranging again.