I have aussies as well as GSD's, and love them both. I don't think having a dog that "is to smart" would be a problem for anyone! "Brains" make everything so much easier!
Border Collies are great, and I'd probably have one if I didn't have 4 dogs, they require alot of mental as well as physical stimulation and are really 'into' their owners which is certainly not a bad thing.
Aussies, tho I will always have them, can have their own agenda's at times, but are smart, energetic, and ready for anything. However, the falsehood IS they love people/other dogs,,sure most do, but I tend to see ALOT of dog aggressive aussies. As one poster put it, it's all about how you raise/train them and they require ALOT of socialisation and training..Borders same thing, the ones I know, the majority just aren't "into" other dogs, they tend to be more "into" doing something..Which again, isn't a bad trait in my book, it's just the way they are..
good luck with your search
diane