Dual working or sport dogs?

[el_andme]

law enforcement is typically where you would find a dual working dog.
what about in the general public - do you have a dual sport or dual working dog?
what are the pros and cons?
i currently train SchH, but also want to have a herding instinct test preformed on my pup. he's been around cattle informally, and would like to introduce him in a formal setting.

 

[Patricia I]

Golden Retriever. I had a female for seventeen years that I can never replace.

 

[K9Resqer]

I know several dogs that do agility and flyball. Or agility and conformation. Or agility and obedience. I'm hoping once we get going in agility I can get my dog into flyball too.

I always find it fascinating to see an agility/obedience dog working. Seems like it would be difficult getting the dog to know when to be by your side and when to be taking off over jumps. But the dogs I've seen in action all seem to know the difference.