Go Linus
I love agility (ok so I didn't get too far but I really really loved doing it with Penny). And bypassing a chance for a cookie is impressive! a sure sign he must love doing it not just for the reward at the end (doing it is rewarding).
And good information about size and build. One of my concerns with getting another lab is just that, the things I want to do may not be suitable for a big dog (though even if I get a lab - i really really want a dog under 70 pounds that I can carry if needed). So good to hear that if well conditioned and well "built" it shouldn't cause issues (no more than other dogs per say).
honestly even with Penny, I had never planned to jump her at the regular height. I forget what it was for her. I thought it was ridiculous and she was a smaller dog (45 pounds). I think i'd only ever work a dog on the lower options. Unless years down the road I get a super dog and want to go far. But to just compete for fun, i'll stick to lower.