Again,
not to belabor a point or downplay any book, but this is a tough exam to pass reading a book. you need to PRACTICE, PRACTICE, PRACTICE. Any course that gives you a TON of practice is good. I am familiar with just jensen, ho, and Just Oral Boards, so my vote is for Just Oral Bds because they provide tons of practice and very little lectures, whereas the other two are mainly lecture based. whether its reading a book in a coffee shop or sitting in an over AC conference room this summer, I do not think you will learn like that.
I agree with FFP that The Anesthesia Guide by atachabhian and Yao and Artusio are good books to use alongside a good course, but don't think by themselves they are enough. I also agree with hudsontc that practice exams with colleagues is useful, but be careful who u choose. someone at ur work may offer to give u a mock exam and themself not know what they are doing (i.e. never say "x" on the exam even though you could). The board examiner (singular) at my residency was too cocky to help and if he did he made u feel stupid. don't think his role in my prep was worth anything.
I'm biased bec they helped me pass but just oral boards is the way to go in my opinion, but both ffp and hudsontc have very relevant points here.