My daughter had a Yorkichon first & I just fell in LOVE with his personality.  He was the Best to train.  I got Bella almost a yr later.  The breeder did have breeding rights & also breeds yorkies.  They have the same father (yorkie), but different mother (bichon).  They do look entirely different.  They both have the sweetest personality, easy to train.  They were both trained to use puppy pads with no problems.  Bella is now 2 & she never has accidents in the house.  She's a sweetheart!  We recently took her with us on a 7 hr car trip & she was an angel.  So far, no major health issues.
I do LOVE yorkies!  My stepdaughter has one that we adore.
There is debate sometimes over mixed breeds.  You are smart to do your research.  It is your decision.  I wish you the Best!  Hope u stay with us @YT & share yr new baby soon with us......whatever yr decision may be!