Assessing drive in a puppy?

I think I may try to get some video myself - might help myself see it more objectively and I could get input from you all. :)

Laddy, when he tugs, looks a lot like the pups on the video: focused, could care less about what he's running into or over, etc. and bites fully and calmly.  Usually there's a bit of play growling.  However, he's not doing that for 3 or 4 minutes continually with quite that amount of distraction, nor have I tried lifting him off the ground completely (he will hold on when lifted off his front feet for sure). 

If it's not horribly icky out tonight I may try him out by himself with different surfaces and distractions - those videos really gave me some good ideas on ways to see how intense he really is. 

I am encouraged by the fact that he remembers exactly where the tuggy is kept and will search for it first thing when we go into my office (where it stays on my desk lol).

Liesje - do you keep all toys except chewies off the floor at your house so that Nikon only gets soft toys in training?  It was mentioned in a Susan Garrett article about building toy motivation and made me wonder.  Laddy has a ton of toys out right now because it's the only thing that keeps him from mouthing myself, my husband, or the girls unmercifully, but I don't want to be working at cross purposes either.

 eta:

Agile - I have no idea about his background before 8 weeks, but he was kept in a shelter kennel (27" by 27" by 27" usually) for pretty much 2 months straight and thus likely got little to no tug or much of any other play with people and toys during that period.  Puppies generally get toys 2-3 times/wk at the shelter and are only taken out of the kennels when a potential adopter wants to interact with them due to disease concerns.

I keep all Gappy balls, tugs, and rags put away.  I take them out, I put them away.  He has Cuz balls and stuffies that he plays with on his own or with other dogs.  Hardcore competitive SchH people would gasp if I told them that, but having my dogs be balanced household companions supercedes scoring points in sport.

When I take out one of the "special" toys, there is structure to the play.  Nikon has done it enough to have learned to be proactive.  He initiates the game by barking and getting excited.  This animates the toy.  You don't want too much of the other way around, always having to work really hard just to get the dog going.  He doesn't take the tug/get a bite until I (or the helper/trainer) offers, when the level of drive is acceptable.  There are all sorts of things to watch for and do, depending on what you want from the dog, what you want to encourage or discourage.  For example, I encourage countering to a full bite, but I discourage chomping/chewing on the toy (if he does that I let go and walk away, game over).  I encourage him getting his butt way down and using his entire body to tug.  I encourage and reward this by slowing moving toward him, so it feels to him like he's "winning" and pulling me.  When he gets going on this, I slowly grab his collar and apply pressure.  This is where the frustration comes in.  I do not choke him off a tug, the pressure builds frustration which encourages the grip and the drive.  I hold him this way for maybe 2-3 seconds, set him down, and let go of the toy so he's won.  We are working on him holding his toys with calm grips, so if I can I sit next to him and rub his chest while he holds the toy.  When he spits it on his own, I snatch it up and we start over.

 Neat information.  I need to do more of this kind of training with my dogs.