Partial Differential Equations and Group Theory: New Perspectives for Applications

I'm beginning to think this guy has a point (or two). It's not my area so it's hard for me to judge, but I can't find any real mistakes and, behind the terrible writing, the guy has good mathematical taste. All that's missing is a pithy abstract treatment; he does the concrete level so well. In any case, it's lots of fun trying to figure out what he's on about and it beats reading anything else on classical mechanics and field theory (including Arnold). Please read the book straight away and tell me what you think!