There is a good description of their temperment and training issues in a training book called "Good Dog, Bad Dog" by Siegal and Margolis.
The pages about Weimaraners is about 2 1/2 pages long, so if you go to the bookstore you can probably read it there and get the idea without buying the book.
The basic explanation in the book: They are very loyal and good with kids. They need a lot of exercise. They are stubborn and strong-willed. Chewing problems are common. Without great patience, it can be a difficult struggle to train them, They must be trained at a very early age.
He goes on to say they there are many people who love these dogs.
A girl down the street from me has two of them, I don't see them often cause she either keeps them inside or in the back yard. They are certainly beautiful dogs, but hers seem to do what they want and scarcely pay any attention to her (altough that is true of any untrained dog).
My advise would be to think about what characteristics you want (and need) in the new dog and then do some research on the different breeds before you make any decision. Then be sure to train it early and consistantly.
Good luck.....