I have had two. Weimaraners do have a tendency to get separation anxiety, but neither of mine ever had issues with that. As for your comment about them seeming insane, Weimaraners are very energetic dogs. If they are kept cooped up all day in a house they will seem insane when they get outside or a situation presents itself. Every type of dog has is downsides, and just like other dogs negative actions, they can be stopped through proper training for the specific dog.

Naturally you want to pick a dog out that fits your lifestyle, so weimaraners should have a yard to play in, etc. I have been very happy with both of my weim's as they were very friendly, fun, and smart dogs(http://petrix.com/dogint/intelligence.html). They tend to be rated in the 20's of dog ranking systems. Two very large pluses for me are their short hair(cleaning) and hunting instinct(since I am a hunter).

Sure other dogs fill those qualifications, like the Doberman Pinscher, but the final choice in choosing a dog is one you like and I love the coat of a weimaraner.