I want to love Google-branded, HTC-manufactured Nexus 9. But ours is a contentious relationship. N9 is not a bad tablet; others offer better value and performance for the price (or less), with Apple iPad mini being high among them. That said, if pure (aka stock) Android is your thing, there is no worthy alternative. Just prepare for a few compromises, particularly if moving up from Nexus 7.
In his November 2014 review, my BetaNews colleague Brian Fagioli calls Nexus 9 “magical“. I can’t agree. During my four months using the tablet, response occasionally hesitates and WiFi too often disconnects. Last week, my N9 received the newest Android update, which somewhat resolves both problems. I purposely delayed this review, waiting for v5.1.1.