My dad once said to me, "You give a lot of books three stars." I do.
The beginning of the book is strange. 1. I don't associate beer with the circus. Peanuts, yes. Beer, no. 2. There's some slight xenophobia with regards to Josep and his name.
The rest of the book is good though. I don't think I read this one as a kid, though I'm not positive that I didn't. It has one of the most graphic battle scenes so far in the series. Super gross.
Some discussion/speculation under the cut. Spoilers as usual.
I think Rachel's dad is moving to Denver. It makes sense given where the Animorphs live and the distance and description of his new town given. Which might mean KA Applegate had their location in mind pretty early (in the first few books it their location didn't feel settled. Just a kind of vague anyplace).
Morphing exhaustion is back in this one. It might not have been mentioned in the last book because Jake was too busy being infested to know how exhausted everyone else was after the mission.
The time travel in the book is strange (going into the future might be even more complicated than going to the past...), but if you accept that it's more of a premonition based on one choice made at one point in the past it makes sense. Or at least I was able to quit questioning everything once I decided to interpret the future that way.
Do the Yeerks have any security system/cameras? And how clueless are the human-Controllers? I mean, everyone demorphs to human right in the middle of the Yeerk pool yet no one recognizes that they're not Andalites?