I ended up going 9-11, with one more loss due to misplay.
Summary: This grinder has good matchups against decks with minimal control, like monoaether and hard rushes and healing-only stalls, but it's extremely one-dimensional, so if you so much as sneeze at it the deck falls apart. Repeatable CC like Otyugh/Eagle's Eye, one well-placed Deflag against your last Sundial, early Discord/BH/Pest, etc. That's a sufficiently large proportion of the arena for the deck to not be a viable over-90% farmer.
Game 1: Timebow. Early Otyugh and judicious use of Steal locked the field down for the entire game. LOSE
Game 2: Monoaether. Things looked good right up until the Sundial chain broke one turn from victory. LOSE
Game 3: Pestal. My opening hand only had one creature, so the quanta drain was too much despite their fractalling Damselflies. LOSE
Game 4: Firestall with Sanctuary. I got a lot of SoFr in the opening hand. WIN
Game 5: Luciferin/rustler life rush(?). It was really low on damage, so there wasn't much of a threat. WIN
Game 6: Monoaether. Ended predictably. WIN
Game 7: Mono-air with flying Eagle's Eyes. They locked down the field quickly. LOSE
Game 8: DBH speedbow. I was unable to play SoPa for too long and the Sundials eventually ran out. LOSE
Game 9: Mono-air with flying Eagle's Eyes. See game 7, with the addendum that they also brought Thunderstorms. LOSE
Game 10: Time/Earth control(?). A series of Rewinds eventually got past SoFr, setting my damage back just a bit too long. LOSE
Game 11: Monodark. Ended up drawing absolutely no damage or Pests until it was far too late. WIN
Game 12: Air rush with Deflag splash. Ended predictably. Derped and Sky Blitzed without removing SoPa, but I didn't really have enough damage for that to matter anyways. LOSE
Game 13: Monofire rush. I didn't draw any Sundials, but given all the Deflags they probably wouldn't have helped. LOSE
Game 14: Mutation deck. Early Discord stopped SoPa. LOSE
Game 15: Mutation deck. In retrospect, I really should have broken SoPa earlier; this loss was entirely my fault. LOSE (by misplay)
Game 16: SoFr/Wings Vampire Daggers. I completely derped and somehow forgot to play SoPa for the first few turns, but their damage was really slow so I still ended up winning. WIN
Game 17: Uh, monolight RoL/Blessing rush? No real threats. WIN
Game 18: Morning Glory deck. No real threats. WIN
Game 19: Armagio/Acceleration. Fortunately SoFo never saw play and Black Hole didn't come out until after SoPa was already on the field. WIN
Game 20: Monolight stall. No real threats. WIN
Game 21 (to attempt special spin): Monodark. It had far too many Steals and took literally all the SoFr and SoPa. LOSE