I love BR, in fact, is my favourite, but I understand your feelings because it's a different album, not classic "Ozzy style". If we take out our personal taste, i would say the changes in BR shows how good is Ozzy: capable to create new music after 40 years and the lyrics are a message to the world.
About Zakk, well, I would say it's not his better performance but, again, I thing a good guitar player should be able to change