When I got my 5 year old mix (pretty sure she has pit in her, so she's very STRONG!), she was already 4 months so I didn't get to train her immediately. She didn't walk well at all, would pull me and would get distracted easily. I reluctantly started her on a pinch collar. It was great, she learned fast that if she pulled me she would feel a pinch. I didn't really feel bad putting it on her because she pretty much stopped pulling me, so she rarely felt a pinch. Now 4 years later, she is fabulous! I don't need the pinch, she walks by my side with slack in the leash, and only sniffs when we get to "her spot".
My puppy still isn't used to the leash yet, but is doing pretty well for 8 weeks. I do short walks with him because he just isn't ready for the long walks that my 5 year old goes on. I'm keeping him by my side as well. My main problem walking him is that he always wants to stop and scratch his new collar and won't "do his business" if the leash is on him!