You're right, it's a 2.5-10 scale. For future reference, the median review score for a hotel on booking.com is around 8.1, based on a bunch of scraped data. Varies a lot by location, though. Business travelers also tend to rate almost a full point lower than any other group (family, couple, solo, groups), but I'm not sure if you can break out that information on their UI.
My personal heuristic for using booking.com is rating > 8.0, then skim over the negative reviews for dealbreakers. Bad ratings for restaurants or concierge or whatever is fine for me, but "room reeked of cigarette smoke" is not. Positive reviews don't really have a lot of signal to me, but YMMV.
My personal heuristic for using booking.com is rating > 8.0, then skim over the negative reviews for dealbreakers. Bad ratings for restaurants or concierge or whatever is fine for me, but "room reeked of cigarette smoke" is not. Positive reviews don't really have a lot of signal to me, but YMMV.