What's your "spec-sheet" dealbreaker (e.g., no sapphire, no buy)?

This is a great question, and I’m having more trouble than I thought I would in answering it! I would probably that if it’s mineral crystal it’s a no buy, but always happy to consider acrylic. Others would be, if it’s sapphire with no or poor AR; and also, though now rare, a pressed inner clasp

Any diver without a decent taper on the bracelet is an instant pass for me. A chunk of 20mm steel with no taper feels like wearing a handcuff.

date windows that aren't color-matched to the dial always feel like an afterthought to me...

I cannot stand press-fit casebacks on anything over a couple hundred bucks. If it doesn't have a threaded screw-down caseback for at least 100m water resistance, it usually feels like a toy to me.

I'm getting really pickier about thickness lately, so would you consider anything over 13mm for a non-diver?

For me, it's gotta be a movement I trust. I've had too many headaches with off-brand movements giving up the ghost, so STP or Miyota 9-series at a minimum, or I'm probably out. Even some cool designs from brands like Traska or Zelos won't tempt me if the movement isn't solid. That said, I'm okay with a well-regulated NH35 in a more affordable piece.

If it has a diver style bezel, it better rotate. Any function that is there that is non-functional is an immediate turnoff.