dreamer26 posted another thread about her sister and another friend, both married to alcoholics, having completely different experiences and thus not finding the support she needs from them.
I think that may be more of a function of the relationships between dreamer and these folks, and also the difference in the way the disease progresses.
But I do think it can be very helpful to find spouses who have the same Drug of Choice. It seems like that has a play in how we family members experience addiction. ie; cocaine addict behavior and the surrounding issues created seems very different to me than IV drug user behavior, at least until the coke addict becomes an IV drug user. Example: When one of my brothers only smoked pot he was not nearly as hostile as he has become since picking up other substances. The chaos is different.
But also think people having dealt with addiction for longer periods of time have more insight and understanding into the experiences that we all have in common.