Actually, I just came across this book, but all I read is the table of contents, and that's RF anyway which is not really what I've studied.
>Do you encounter a problem that modern control seems a better option?
I think that until I understand modern control, I will not be able to answer this question.
However, I am really just studying modern controls because I want to have as wide a breadth of engineering knowledge as I can.
But anyway, I guess the questions still stand for me which are: Are LMI methods ubiquitous throughout controls? If not, why not, and if so, why study the topics in Kirks book? How is LMI control related to calculus of variations?