I'm similarly underwhelmed by Xanathar's. I like the presentation of the book and some of the new concepts introduced in it, but it feels like it would be better if it were simply a digital release with the new stuff. What 5E really needs is a PHB 2.0, all the additional revised content in it.

People complain about how PHB+1 is so limiting, but even as someone that has all of the books, accessing this information even as an experienced player and DM is a headache. If I want to truly understand one of the new classes in XGE, I have to use it and the PHB side-by-side as none of the base class information is re-printed. Given this and AL's own scattershot documentation issues, it's a massive pain. Volo's and EEPC weren't as bad, as they only presented new races and spells.

While initially PHB+1 sounded good, the scope creep and cash-in nature of splatbooks is starting to creep back again. I'd love to see just a 'One Book' rule whenever Sixth Edition rolls around.