Thanks for the help everyone,
Thanks Vislor, I thought Tony was a really good guy and seemed to know his stuff when I went down to visit but its good to hear that other people who know a lot more obviously agree.
Its good to hear that people who provide enough excercise seem to get on pretty well with them in the house. I'm just trying to build up a picture of how this new pup will fit in once he's here but I think im prepared for a rocky ride till he matures now

I think whats scared me is the amount of chat about working line/showline and how different they are!
The reason I decided to go for a working line is that I live in a rural area and have a very active lifestyle which I think a more athletic dog would enjoy. Typically weekends are spent camping/hiking in the lakes and during the week its rare that my current dog gets less than 4 miles walking off the lead and chasing rabbits and pheasents as they appear. Also I really love how sharp and alert they always appear, I'd like to train tracking and obidience work with him as well as a good range of fun tricks and games. Our deerhound has got to about the limit of her willingness with tricks and obidiance and I really want a dog that will have the scope to do all the things I'd like to do in the future. My deerhound gets about half hours training on an evening but sadly she gets bored after that
I think whatever I chose it was always going to be a GSD but I guess im just looking for some reassurance I've not signed myself up for something I cant handle!
Ps: Stuart, Id not heard much about using a treadmill to supplement excercise before. Do your dogs enjoy it? Do you just use a human treadmill with a long base or a specific dog one? Maybe sounds like a silly question but do they not get bored? Only becasue I know i do lol