There are plenty of folks here who have DDR dogs as active (active being the key word) family pets. It all depends on the dog, so find a breeder who knows their dogs well enough to match you with a pup with a temperament that meshes with your lifestyle.
May I ask why DDR specifically? Most people, unless they're deeply involved with the breed/sport/etc wouldn't be able to tell a DDR apart from another working line by temperament and probably not by looks, either. It's become something of a "buzzword" these days... don't let it limit you in your search for a breeder. Use it as a guide if you're really set on it, sure, but don't count someone out who produces great, stable dogs just because they're not the lines you think you want.
Delta zur Bindenburg- 11/15/13
Gentle Tripp- 6 yr old OTTB mare