Lol wtf I've been doing it all wrong. (Face Palm) Awesome tutorial! Super nitpick: To critic the model, does that eye patch/thing fit on his eye ball - looks mighty close.
I merge the tools when I feel comfortable with the overall silhouette and I have my major muscle and bony landmarks in place. The goal is to do a good portion of the thinking in the initial block in so that afterwards its a simple job of filling in muscle details and secondary forms.