I kept AB'S for 15yrs starting in the late 90s.If you get a good one they make a very good dog but unfortunately I'd go as far as saying 90% of what's being bred is pure shit with some kind of health or temperament issues.Wifes had 2 ,I reckon your 100 percent spot on, temperament is what should be considered not looks. Loads of twitchy Bulldogs around. Same could be said with rotties as well I reckon.
Some of the spitz breeds as well make good guard dogs.
i think we have just been lucky with him to be honest and i doubt i would rush to get another one after he's gone.he's devoted to my kid