When I buy puppies I actually look for the higher energy ones. Typically the best hunters are the ones you would consider ADD. All the puppies I've bought, trained and sold were very hyperactive as puppies and still retain a very high energy level as adults.
However these puppies, once trained, do calm down somewhat inside the house. My dogs do not run all over the place in the house - in fact they tend to loaf about the house similar to English breed fashion. The difference is when they're in the field. Their higher energy levels allow them to train more intensely and learn more quickly. That same high level of energy allows them to work and hunt for longer periods, be faster, more agile and a more dedicated hunter. They are also more willing to push through the nastiest of brush and thorns to seek out that fallen bird... because they are more energetic and more headstrong.
I also find that this quality in labs also makes them easier to train. A lower energy and calmer lab (ie. English breed) tends to learn more slowly and is less tolerant to adverse conditions when training. As such they tend not to be as strong a hunter and are not as intent on finding and retrieving the game.
Now about being ADD - none of the dogs I've trained could come close to being ADD despite having much much more energy than your typical English breed lab. They would make an English breed lab seem slothly and lazy yet they listen intently, are completely obedient (I can call any one of them off a bird even if its right next to them and direct them somewhere else so long as they are in sight and hearing range and even if they're not within sight I can stop them in their tracks with a single command if they can hear me). Everyone who has met dogs I've trained comments on how amazingly calm, relaxed and obedient they are and then are even more amazed that these dogs can hunt for 12 hours, running 10, 20, 30 sometimes more a day in search of pheasants, ducks etc. and still have energy to want to hunt more.
I don't consider the American field breed of labs to be ADD or flighty. Their energy levels are exactly what I want in a hunting/sporting dog. You just have to be able to train it and mold it to suit your needs. My dogs don't jump up on people, don't lick, don't go on furniture, sit and wait to be allowed to eat and never leave my yard unless commanded to do so. Inside they prefer to sit and slumber either next to someone's feet or inside their crates. Doesn't sound ADD to me, does it sound that way to you?
Really its all about being able to train the dog properly and maintain that training. A lot of do it at home trainers don't know how to properly train a dog. Heck a lot of professional dog trainers (you know the ones toting all those diplomas/certificates from internet dog training schools etc.) don't know how to properly train a dog.
The 'high energy' you refer to, I like to refer to as 'flighty'. IMO, this 'high energy' or 'flighty' does make them harder to train them compared to the more subdued acting European breed counterpart. Seems the more pure bloodline dogs stay focused better.
Its only flighty because the owner/trainer has allowed the energetic levels of the dog to turn into flightiness. As I said before its because most dog owners do not know how to train dogs properly. My dogs are VERY high energy but definitely not flighty. Also about pure bloodlines - in labs if bloodlines were pure they'd all be high energy and be of slenderer proportions... that's how they were originally. Also let's not talk about just the US ruining dogs. You should look at how the English hound looked in Great Britain 100 years ago compared to how it looks now... and whether or not it could still hunt like it did a century ago. Conformation in dogs is what destroys dogs - all over the world - not just in America. In fact the Americans got the idea from the Brits first...
I will give you that in America you can't really find a GOOD GSD, Rott, Doberman, Malinois etc. Most of these breeds have been completely ruined by conformation breeding. You WILL have to buy European for that and even then you have to get them from a breeder that breeds for utility and NOT for conformation. That's the tricky part. A lot of breeders will say they breed for both. Frankly I have found that to be a load of BS from experience - at least in sporting dogs. With labs I won't buy a lab from Europe. It's an American field breed or not at all for me. A lab that will typically win championships and titles in conformation will only be a mediocre hunter at best. None of my labs that I've trained and/or trained and sold will win conformation shows but most of them are already Master Hunters and many of them are already Field Champions or Amateur Field Champions. There's a couple well on their way to becoming Master National Champions... of which there are currently only a little over 100 dogs in the entire nation that can claim that title.