he is very playful but not mean. he can be a little rough but you got a pit so i dont think you have anything to worry about there. as a puppy all he wanted to do was play but after growing up a little and getting nuetered he has calmed down a little. he still loves to run around, play fetch, and rough house the only difference now is that when everyone is sitting around calm he does too instead of jumping on you begging for attention.
i dunno if all mixes like him are tough or if its just him but he is extremely tough. he once got a metal pole stuck thru his lower eyelid when he was in his cage at night. those were some of the most bone chilling squeels from a dog ive ever heard. his face was litterally stuck to his cage and he was using all his strength (which is supprisingly alot for his size) to try to get free but in the process he was just ripping his lower eyelid. well once we got him out he was bleeding a little and we put him down to lay down but he just got up and started rough housing with my other dog. (we took him to the vet and thankfully no damage)
and he is a VERY dense dog. he is about 3 or 4 inches longer than the length of my elbow to the tips of my fingers and he weighs more than my brown dog. (keep in mind shes half german and beagle. beagles can get pretty fat and germans are pretty big too) my black one weighs probably 35-45 pounds. all muscle too. not an ounce of fat on him. and he has a bigger neck than me. his is about 17 inches around.
both of his breeds are also notorious for being hard to potty train. and the french bulldog in him gives him EXTREMELY bad gas. those types of dogs swallow their food whole and then chase it with ALOT of water. which in turn gives them gas. ive kept track a few times and he has drank water non stop for over 4 minutes.
got anymore questions? i love dogs.
edit: oh and he is a good gaurd dog too. not very good protection wise due to his size but he will let you know if anything is going on.