I own both, and I love both. I know what is said about both breeds--personality-wise, and generally speaking it may be fairly accurate, but from my personal experience they are very alike. Let me just share a few personal examples. I almost don't have Lulu because we had a Maltese, Lacy, when we got Lulu. When I took Lulu to the vet for her health guarantee check-up, that vet asked me was I aware that I had gone from one end of the spectrum to the other. I asked what she meant. She said did I realize I was bringing the worst-tempered dog into the household with the mildest-tempered dog. She told me she supposed it was possible but would require endless training and endless socialization on my part. I had already read that Chihuahuas were clannish, yappers, territorial--all not favorable reviews of the breed. I told my husband Lulu loved Lacy now at 9 weeks old, but what if she turned on her at 6 months old? I couldn't take a chance, and we gave her back. Long story short, we couldn't live without her, and decided whatever it took we would make it work. Lulu loved Lacy until Lacy died, and she mourned Lacy so much her personality changed, BUT until the day Lacy died, Lulu could NEVER touch her if she was just lay down without a growl. When we lost Lacy we got Gidget, another Maltese. It took Lulu a month or so to get used to Gidget, but she loves and protects her now. Also, Lulu has always let Gidget lay all over her without a sound. Gidget is a TERRIBLE resource guarder. It doesn't matter if it's food, toys, or antlers. Lulu will back up and let Gidget have her food. Lulu by herself barely barks if someone knocks or comes in the door, but Gidget barks a lot and loud and Lulu will bark more with Gidget around. They are both equally cuddly and adoring of us, but I think Lulu sits in our lap longer/more at night. Gidget will get down and get in her bed sometimes. I said all this to say--do NOT let a vet give Chihuahua a "bad wrap," and don't believe everything you read on the internet concerning the breed. I love them both, and if you are up for the grooming the Maltese require, I would suggest one of each.
Life is better because I have a friend like you.