We have a seven year old pure bred, by far they are the smartest dogs Ive seen. A great story my gf told me:
Old neighbors, who owned a bunch of chickens, moved out one day & left them behind. Th chickens would pop in & out of the yard periodically, and one day not too long later, Xena (the shepherd) trots in the house & very gently drops an egg into her hand from her mouth. She then leads her out and shows where all the chickens have laid eggs.
Free eggs!
She is also very gentle with kids, and has the most intimidating bark around, most people are afraid to step into the yard (even friends that have been around for years).
Overall, my favorite dog Ive been around.