Hi wyvernblade,
we got our dobe when she was 10 months old. She is very intelligent, and an extrememly fast learner. We have not done any formal obedience training with her, but we have taught her a bunch of tricks that we find come in handy. She is quite food-oriented, which makes her easy to train. I would like to do some agility training with her - I think she'd love it. When she's old enough we might give it a go.
Temperament wise - she is a big sook who loves being with us. But she is also quite happy to spend hours napping under a tree or chewing on a bone if we are not home. She is not at all highly strung, infact I would call her laid-back (except when someone is approaching her territory, when her guarding instint comes to the fore and she barks at them).
I have met several other dobes, and while I can't tell you what they're like to live with, I think ours is fantastic!
jbbb