It's really neat to be able to sort by size and content policy, but as one cannot sort by topic I'm not sure it's very useful for most people. At least for me with my very plain preferences, I was given a very long list of suggestions.
I think the [https://joinmastodon.org/servers](official Mastodon version) is still pretty great. You can choose to filter by European servers, and then whichever topic you're interested in second. :)