White Boxers are frowned upon in the Boxer breeding world. I have owned two boxers (I have one right now named Maggie) and I don't understand the "less a companion dog" comment. Boxers are very loyal and loving. Anyone who grew up with a boxer as a child has stories about how their father couldn't spank them when the boxer was near. They will allow no harm to come to a child. I wish I had one when I was growing up. My first Boxer would put some teeth into my wife's butt (just enough to get her attention) if she started yelling at me. God I miss that dog.
And they have health issues as well, such as deafness. They are gorgeous though IMO. Anyway, I'm a long way from deciding. Besides, like was mentioned earlier...I think a dog chooses you.