Yeah I knew about the weight, Ridgebacks are right around the same there... but the extra couple of inches of height would be beneficial. I should mention that I live in Spain and the Dobermans here tend to be an inch or two taller than their US counterparts as well as weightwise, they tend to be about 5-10 lbs heavier.
I'm currently partnered with a 180lb Mastiff bitch who is 30", so a 28" male Dobe would be fine heightwise I think.
I definitely need a more active dog, I am limited in where I can go and how long I can be out, as my Mastiff, while an athletic bitch, can't go for more than an hour or so (I don't drive) without getting tired and she can't tolerate heat well

Bad thing in Spain.
Actually no I'm not a Vascular Tech, I'm a registered Veterinary Technologist and Licensed Canine Nutritionist
