Hey, long time fan of Sentinels here, played tons of games with every hero and villain. I got my Oblivaeon box some time ago. I read through the rules, gave a look around, and I put it on the shelf. It looks way too fiddly and way too much bookeeping for me to even want to try it.
I've read through several comments on Boardgamegeek, while not everyone agrees, several people tried playing it and were not impressed with the Ultimate Bookeeping Mode of this game. Some reported a single game lasted for hours.
Please note that I'm not daunted by complexity - I like heavy Euro-style games. But the complexity has to be worth it. I'm not a fan of chasing consecutive card triggers like the rabbit in Wonderland.
I was wondering if I'm exaggerating things and whether Oblivaeon is not actually so bad. Some positive opinions that the bookeeping is worth it, and the gameplay is fun would encourage me to give it a try.