I also have a Morkie! She is half Parti Yorkie and half Maltese. She has marking like the Parti Yorkie, but looks more like a Maltese. She is so hyper sometimes I think she's bouncing off the walls! LOL I personally think she is very smart. She knows all the basic commands including more advanced commands such as, play dead, roll over, dance, sit pretty, jump through a hoop, and many more!
Potty training her was a breeze but I've herd different from other people. You can train your puppy to ring a bell whenever it needs to go out, but mine will bark until I go out with them. LOL