My Ravnica Allegiance prerelease pool probably could've beaten any opponent in the room... except for the round clock.
I took an Orzhov kit and ended up with the most obvious Esper pool imaginable. Ethereal Absolution, Sphinx of Foresight, two copies each of Sphinx's Insight and Archway Angel, and all my Guildgates were on color (two Orzhov, two Azorius). I had a pretty fantastic suite of removal as well, so although I was lacking in the Afterlife creatures to really make the Orzhov grindy deck sing (am disappointed I didn't have enough creatures to make Priest of Forgotten Gods worthwhile), I could gain life and draw cards and easily last into the late game where Ethereal Absolution could take over. One of my Gruul-splash-Black opponents lamented to his friend how I'd gained 14 life in one game.
The issue, of course, was the clock. Every match went to game 3 and went to turns. Both matches I probably could have one with 1 to 3 more turns of attacks (Absolution is NUTS) but didn't have that opportunity. I should have reported a draw but I don't treat prereleases at this store as serious business and so we just high-rolled to give someone a win. This store plays four rounds and prizes are for 4-0 and 3-1 so draws do nothing, and as I said these events are not serious business to me. I lost both rolls and dropped after round 2.
Round 2 in particular is a big lesson-learned moment. I was unable to win because I assigned one too many Spirit tokens to block. We were in turns and I was in a hurry to end the game, so I did not properly take stock of how many cards my opponent had in hand and how many tricks they could pull to push lethal damage through with their trample creature. I also had not been doing the combat math on how much damage I could do on my next turn, so I did not realize that I'd be 2 short of lethal if one of my Spirits died in the block. So, especially when you're in turns, keep track of your opponent's mana, their cards in hand, and always run the combat math in your head to figure how you win.
Incidentally it'd be pretty nice if Vintage players could go nuts over Lavina and drive the foil price up for me.
In other news I really need the Orzhov Guild Kit when it comes out next month. My Teysa, Orzhov Scion commander deck has been one of my favorites and I really want both the alternate art Teysa and to be able to run every Teysa, both Ghost Dads, and Kaya in it. It'd be an interesting challenge to try to make the 97 of the Teysa deck such that I could randomly choose any Teysa to be the commander before play.