I have a Boy son and know someone with another Boy son (her dog is out of a really nice Karthago bitch, she is also a very nice person, she actually did the AD with me so I could run both my dogs at the same time and she handled Pan). My Nikon is almost 4 years old but I had contacted Bill and Jen before I got him about getting a dog from them and then decided to go a different direction at that time (show line). When I saw Boy in person for the first time in 2009 I was very interested in him so I got Pan (Boy/Hilde) born August 30, 2010.
Pan is high drive, high energy. He is very stable and I mean that almost to the extreme. Sometimes in protection we struggle with pushing him to the next level because he is SO complacent and happy, he's difficult to really unnerve and pressure into strong defense. But, in my mind this is not a bad problem to have. I chose to go to Boy because I was looking for a high level sport dog that would not be a problem around kids, lots of people, living in the city (people here have no concept of personal space so I can't have dogs that are very territorial). In my mind Pan is too friendly for a GSD but again, this is not a bad problem to have and he is turning two in exactly one month so there is still plenty of time for him to mature. He is still aloof in the sense that he only listens to me and prefers me, but he's also very receptive to attention and a very social dog. He's good with kids and I think he sees himself as one of them, not a guardian or protector but he likes to play *with* kids. He has never, ever been mouthy. I would not describe Pan as "calm" but he is respectful. Pan has high prey drive and (IMO) a lower threshold than I'm used to with Nikon. However I do not find Pan hard to control. I say his name and he will come to a screeching halt and come right back to me. He's just super happy and willing to please. He is a tad dumb meaning that he learns differently than Nikon. He's not real easy to free-shape. He likes to be shown what to do, either through luring or compulsion, and then he will have a breakthrough moment and is very reliable after that. For example it took me months just to get Pan to TAKE the dumbbell in his mouth but once I got him to realize all I was asking was to open the mouth and grip the dumbbell, he progressed to very fast, correct retrieves in just a week. He is very drivey and willing to learn but because his threshold is lower I think he gets too highly aroused in drive rather quickly which sometimes blocks his ability to really problem-solve and do freeshaping exercises, but even so I think he's ahead of the game (he was ready for his BH and had to wait because he was too young). He is behind in tracking because I hate tracking and it's been so hot and dry we just haven't tracked.
Pan currently does Schutzhund, flyball, and dock diving. He's the fastest U-Fli German Shepherd dog in North America (he runs 3.9) after just a few months of training. He set a new breed record in his first tournament. He is 2x SG rated, dentition SV and USCA certified, a-stamps A1/normal and just saw his ZW score posted as 76. At 23 months he's 71lbs and is starting to fill out. I've been keeping him lean for flyball but can't stop the inevitable. I LOVE his color (he's not a black sable but fairly dark I think). He is starting to get more masculine though I believe will be smaller and lighter boned than Boy. Growing up he's been 10-15lbs lighter than his littermate Rocco (the other Schutzhund prospect male from the litter I almost got).
Hopefully that helps, if you have specific questions, let me know. I'm happy to be honest about what I like/dislike about my dogs. I will say I am totally happy with Pan and have had no surprises which tells me I did my research
I am on vacation but will try to check back.
This is the most recent photo of Pan, watching the Olympics last night (sorry about the eyes, was using the crappy camera)