What makes or breaks a hotel stay for you?

I'm Oriol, the maker of OKstays. On Saturday I'm relaunching it as OKstays 2.0, and I'd love your input before then.

OKstays ranks hotels by comfort instead of popularity: 67 signals like quiet, beds, shower, WiFi and AC roll up into one Comfort Score, and five must-haves (clean, comfy bed, good shower, bug-free, safe area) are always on.

Why: a 9.0 guest rating tells you guests were happy on average, not whether you'll sleep. In Dubai, FIVE Palm Jumeirah and Radisson Dubai Damac Hills are both rated about 9 by guests. One is a pool-party resort, the other a quiet hotel out in DAMAC Hills, and OKstays scores them 2.0 and 9.5 for quiet.

Two questions:

1. What's the one thing that ruins a hotel stay for you?

2. Is there a comfort signal you always check that most sites ignore?

Every answer helps decide what OKstays scores next. Thank you!