I have two yorkie boys, and they have had no health problems whatsoever and were both easy to housebreak. I have had some behavioral issues with Jackson, but they have been easy to correct. You have to be willing to spend alot of time and alot of work, but that is true with any breed if you want them housebroken successfully. The key is to correct bad behaviors right away.
The first thing you have to do (if you decide to buy one) is choose a good breeder. Don't buy one from a pet store. Make sure you are getting a quality yorkie with no health issues. Do lots of research first and learn all you can, it pays off.
I am very happy with my boys!
