Thanks for the replies! We intend to get training with the collar. Our local pet store is great with that sort of thing. The owners do a lot of one on one and know most of the pets personally. They will see me around town and ask about that new food we put Congo on or if he liked his new toy. They were out of the vibrating collar when I went to check so we'll work with other methods of training until the order comes in.
We were out at a BBQ this evening and Congo did great on recall for the first 90 minutes or so and then got bored and started exploring. Once he did that, he stopped following commands. We've made the decision that when we go to an outdoor country event (many of our friends have large acreages or farms) he gets an hour to an hour and a half (if he's behaving) off leash and then he gets put on a staked line somewhere close to the action but far enough away that he isn't getting into trouble. He's too curious and too fast for us to let him roam.
Once Congo is exploring a new place or tired of doing what we ask, food is not a reward. We've used everything from bacon to steak to dog treats to kibble. Even if he happens to come when we call, he'll ignore the food and look at us with disdain. :p His primary motivation is movement.
We're taking all these suggestions to heart and we'll see how we can tweak them to suit our B's personality. Thanks again for the help. We really appreciate it!