I'm going to echo what I believe division said a page or 2 ago: the prerelease boxes are bullshit seeing as most people had either a god or a planeswalker.
Too bad planeswalkers come in the regular random boosters, so speculating about prerelease boxes having more PWs in them than just five booster packs is incorrect, statistically speaking. The chance of getting a god card is probably the same as the chance you had of getting your guild's leader in ravnica block (1/8, I believe), so it makes sense for multiple gods to be running around during the prerelease, since they're the only mythic players can get from the special booster packs.
I chose blue for my first event and got the 2/3 guy that copies instants and sorceries, coupled with two UR chimeras, Anger of the Gods, two Mnemonic Walls and three copies of the new searing spear, plus a Griptide and some extra damage-based removal. I rounded my deck out with a white splash for a pair of that instant spell that destroys target attacker or blocker, but the lack of early-game creatures made things a bit hard for me. I got two packs, and managed to trade the pro-blue hydra for a Steam Augury and a fourth neo Spear.
I'd say expensive cards are a thing in this format (at least in sealed), which is exactly the reason why I added my one Demolish to the deck and had decent success with it (even copying it once!). I also found myself not cracking the cog that searches for a land too early, since most of the time I was looking for extra lands required to play my kraken, activate monstrous abilities or play several cards in a single turn (ie: Mnemonic Wall into 3-damage instant).
By the way, that 3CMC artifact creature that rampant growths for two lands at once is bonkers. One of my opponents was lucky enough to have two in his pool, and it performed amazingly every time I saw it hit play and survive until my opponent's next untap step.