Our BT is nearly five months old now and has been an absolute joy. We were told though to be very careful about where we got one as die to the fact they are rapidly increasing in popularity, it's encouraging irresponsible breeders to try and cash in. We got him from a KC registered breeder and he is the most happy, even tempered, intelligent pup. We love him to bits. The only downside is that as a breed they are notoriously greedy so we shut him in the kitchen when we eat and under no circumstances is he allowed scraps!
Mine is 2 now and they are the best dogs ever imo but it is best to know what you are getting.
If you want a quiet life with a focused calm dog who hangs off your every word then they are probably not your breed. They are affectionate and tend to love everyone but the ones I know are all adventure loving thrill seekers be it dock diving or chasing rabbits. They are the original loveable cheeky chappies!
They were bred to be game enough to send to ground hunting but energetic enough to keep up with a hunt on horseback so can be energetic. Ours can manage with a couple of miles but will go on and on all day if required. I'd factor on a good hour as a minimum.
I couldn't own any other dog now but they are livewires. That suits us though. They do like a cuddle though. Mine isn't greedy at all. His lack of food motivation has been our training bugbear to be honest. He isn't yappy unless playing football. He loves football, water, other dogs and generally getting filthy. He toilet trained easily, they are quite bright and quick to learn...unless there is more fun on offer. He has never been destructive.
I think they are a great family dog if you are up for the terrierist full on lust for life thing!