Not to beat a dead horse and perhaps just a point of clarification or, amplification. Training only goes as far as the genetics allow it. Genetics first...training second. There is no "wonderful" dog of ANY breed if he is a genetic liability.
Now, I'm not talking genetic "perfection" - we all know of mutts that were man's best friend - but they had solid temperments...so they're relative genetics in that department were sound - but I did describe, and want to reemphasize what I consider to be "fatal" flaws in any breed and that would be high strung, nervous, etc.
Poorly bred dobbies tend to run in this direction. I don't care a lick about intelligence - mine was smart as hell but when he's constantly bouncing off the walls his relative intelligence is meaningless - quite frankly, it just makes him an intelligent liability and an intelligent pain in the ass
Forgive my snobbery/uncompromising position on dogs; I breed them so I'm very demanding. If more people had my standards, there wouldn't be any bad dogs...just dead bad dogs...or bad dogs that were never born But that's just the breeder in me talking
Anyway, good luck.