I played 2 events.
3-1-1 as Izzet. Good enough for 6th out of 30 or so. Cracked some solid Golgari cards (incl two Loltrolls), but those were completely off color for me.
1-3-0 as Selesnya. Pulled Niv-Mizzet... Again off color and I didn't nearly have enough support in blue/red for him. Great for my Niv-Mizzet (original) EDH deck though.
Golgari seemed to be stupidly stronger than the other decks. They had ran out of Golgari both prereleases I went to though (although I would have picked Izzet for the first one anyway)
I didn't lose to a single Golgari deck at prerelease, played against a bunch as they were the fan favourite, my pools weren't even that amazing, I would say the guilds are pretty evenly balanced but it's sealed so bombs win in the presence of equal skill.
Azorious deck didn't really have many bombs just some detain and a d Sphere.
Rakdos was my 4 mythic pack, opened 2 armada wurms 1 rakdos return and 1 jarad, not enough green/white support for wurms not enough green support for jarad. (I don't double splash often)
Selesnya was my dream pool for that guild, 3 cards that make tokens + the land, a buttload of populate and fog populate (druids deliverance), martial law, growing ranks, the +3/+3 anthem, a bit of removal, and wayfaring temple (pt = number of creatures, when you deal damage to a player populate)