I love your post! Perfect!
I breed Biewers, I've bred Yorkies and I have Biewer "carriers" (one parent yorkie, one parent Biewer) so I see the entire range... to me, the dogs are very similar however I do like what MaryKay said.. the Biewer seems a bit more "humble".. I think that's true.. they don't stick out their chests quit as far as the yorkie.. seem to bark a bit less and do seem to cuddle alot more.. they wake up every morning with the look of adventure in their eyes and seem to ask "what new exciting things are we going to do today"
I put it this way.. if a chipmunk was loose in my porch.. my yorkies would want to go for it and kill it.. my Biewers would also want to go for it.. but they'd play with it and check it out..maybe eventually it would end up the same way.. but not as quickly.
The yorkies (and the carriers) seem to be on the look out.. more "aware".. quicker to respond, quicker to bark, need to get to the head of the line, where the Biewers are a bit more layed back.. take things in stride more, less "stressed".
I have been at shows and in situations where we have put intact male biewers in the same pen or females together in groups as we were setting up for shows etc.. all different ages and no problems.. no issues.. nothing like you would expect. It's really nice to see a heard of Biewers running down the hallways in a hotel just having a race.. unrelated, non familiar Biewers.. all just together running.. it's just great.
I'd say keep up the research but these are a very special dog.. I just can't say enough about them. Once you see one, you'll be hooked for ever, once you own one.. you'll always have one in your life.
Diana