Ok medium/large is relative to the person... I think all my dogs are Medium at 60 - 80 lbs... most peeps would think they are large. Low key doggie? Do you want a couch potato that will defend you if need be? Or are you willing to do a little training and excersize with the dog if need be? In my opinion, ALL dogs can be cuddle partners! Although, most protection type breeds are normally more willfull and not the cuddler type. Yet, you can find a cuddler with the mixes...
That being said, I'm pretty sure that my five mixes would defend me to the death if they needed to. My flat coat retriever may not do as much damage to someone as the cattahoula or mastiff mix, if someone was breaking in she would be in the thick of things.
ok I'm rambling and probably didn't answer your question...