It's largely a joint effort of the community, and each individual user customizing their feed. Beyond filtering, you can also mute (can't comment on your posts), hush (their comments go to the bottom for you) and block (can't comment or PM each other, most drastic measure) individual users. You are basically moderating your own feed, without effecting others.
I love it! It's very interesting way to combat spam and trolls.
I'm also loving the site in general, I can use it on Opera Mini without any problem. Reddit is a pain to use on Opera Mini and Voat is impossible.
It is a mobile browser, yes. I personally use it a lot while on mobile data, because it can work in data-saving mode, compressing images a fair amount if you want it to. Also, it has night mode (basically, imagine f.lux, but for a mobile browser), so when I'm browsing the web late I opt for Opera to hurt my eyes less. Other than that, design wise I prefer Safari, it's got nicer animations and transitions. The difference is about the same as between something like Tumblr with a lot of animations/nice graphics and Hubski, which is rather minimalistic.
I also use it while on mobile data because my data cap per day is 10Mb.