Have trained Dobies, Shepherd and also a Rottie to advanced level obedience, and have to say - I'd rather one of them than a spaniel believe it or not - those in the doggy world would understand. (apart from a water spaniel, which was a poppet and so quick to learn)
Used to do re-training for 'rescue'

large breeds back in the early 90's.
Best combi I had was a Manchester terrier with a young shepherd - they worked fantastically as a team
