I know the feeling. What I like to do sometimes is leave little sketch marks here and there in my art. It's a hassle to clean it all up anyway, and the sketchiness doesn't really take away from the story. It also does make a difference too the type of mood you're going for. For a softer, calmer mood like in the second picture, it's good to have soft, clean lines. For harsher, more rushed scenes or images, sketchiness really contributes to it. Sketchiness is fun, because it shows the work you put into the art. I would just go with whatever you want to do. It's your comic! You have the creative license to do whatever you want with it!