I asked a few pro players on stream and they all preferred Pteramander, so went with that. Wound up with a 2 Pteramander deck that went 5-1 too:
2 x
Pteramander1 x
Gift of Strength2 x
Faerie Duelist1 x
Silhana Wayfinder1 x
Simic Ascendancy1 x
Quench1 x
Essence Capture1 x
Titanic Brawl1 x
Gateway Sneak1 x
Steeple Creeper1 x
Aeromunculus1 x
Arrester's Admonition1 x
Simic Locket1 x
Wilderness Reclamation1 x
Enraged Ceratok1 x
Sphinx of Foresight1 x
Skitter Eel2 x
Rampaging Rendhorn1 x
Biogenic Upgrade1 x
Gateway Colossus7 x
Island5 x
Forest2 x
Gruul Guildgate1 x
Gateway Plaza1 x
Azorius Guildgate1 x
Simic GuildgateOther cards in sideboard: 1 Gift of Strength (never used), 1 Archway Angel (never used), 1 Senate Courier, 1 Sagittar's Volley, 1 Mammoth Spider, 1 Rubble Slinger, 2 Humongulus
Deck functioned smoothly. The only match I lost I think I misplayed too (same mistake as in constructed ... not having an endstep stop with Wilderness Reclamation out, lol). I did lose one game because opponent had shown Absorb the previous round, so when he passed turn 4 with no play I simply did nothing as well, intending to use my Simic Ascendancy, but he had Lawmage's Binding. When he indeed had Absorb for the next turn, I got tempoed out. It's possible my hand simply wouldn't have matched up with his; it's also possible this was simply a mistake.
Simic Ascendancy generally did quite well, it made my creatures surgically better than my opponent's. It was especially good with Wilderness Reclamation. I pulled off one Simic Asccendancy win with my back to the wall, at 5 life against an Ill-Gotten Inheritance. That was epic. Enraged Ceratok also overperformed. The blocker clause meant it could attack into deathtouchers, always getting more and more counters from Wilderness Reclamation. Pteramander was ... eh. It did get adapted some times (I realized midway through the run that I can actually adapt it with 4 lands out if I have Wilderness Reclamation in play), but it was very mana intensive and I had plenty of mana sinks already. Biogenic Upgrade was surprisingly mediocre. It did win some games, but for a 6-mana card I was expecting it to be more impactful and sometimes I just couldn't cast it because casting another creature + using Simic Ascendancy would have more impact.
It's possible the maindeck wasn't built right. Many games I switched cards: Steeple Creeper, Silhana Wayfinder, Quench, Gift of Strength - for Mammoth Spider and Sagittar's Volley. I had reasons; I expected long games (= no Quench), opponents had 2/x's (= no Steeple Creeper), opponent had 1/x's (no Silhana Wayfinder), etc, but still. It didn't seem to have a big impact though. They're all filler after all. Against one hyperaggro Rakdos opponent I brought in Senate Courier & both Humongulus (lol) and they won the game.
Gateway Plaza sucked. I had several games where I simply couldn't play it because I didn't want to tap another land for it. For the number of payoffs I had, there's a good chance I had too many gates.
About Angelic Exaltation, one of my opponents had that card, but I was able to keep up with it by virtue of Simic Ascendancy, killing his creatures, and my generically big creatures. I probably got lucky though, he didn't seem to have a lot of creatures in his deck.
On to the next draft!