Like any public forum there's a real mix of people. But it's easy enough to set your filters so you find what you're looking for.
Personally, I don't use KK like a typical dating app, scrolling through profiles. You might as well be on Tinder if you do that! I think it's impossible to gauge a person from a profile and a few photos. Instead, I hang out in the chat groups and see who piques my interest there. I'm more likely to connect with a guy if I can see he behaves well towards others. It's a chance to get to know people before sending a DM. I also check who he has connections or vouches from so I can get references from other women.
I laughed at the idea that 55 is too old. I've dated KK guys from 30 to 56 and their age has no bearing on how attractive I found them. A hot body is all well and good if you just want a hook up but, for me, I want an intellectual connection with my partners. Also, age is no indication of maturity... some younger guys have great emotional intelligence, whereas some older guys behave atrociously.
I tend to decline the vast majority of connection requests from strangers. And, on the odd occasion I've had an inappropriate message, I've reported it to KK admin.
There's a perception that women on a sex site will sleep with anyone but the opposite is true. There's so much choice that we can afford to be discerning and picky about who we engage with.
For me, the community and the social events have made a massive difference. I have a group of about 30 friends, many of whom know each other. We support and advise each other, we socialise, we play together in various settings. We introduce each other to new people with shared desires or kinks. So I might go to a KK party with the intention of meeting new guys but I'll almost certainly bump into some old friends to have fun with anyway.