I'm glad I started training my grip seriously. If you think about it, if you never train your grip then your dominant hand will significantly overshadow your other hand. After all, what do you spend your entire life using for shaking hands and jerking off? I can get about 30 reps with the trainer CoC with my right hand and can't even close it all the way with my left. So I'm training my right hand very casually and murdering my left at this moment.