I've updated mastodon.social and mastodon.online to the latest code in the main branch. You can follow hashtags, translate posts, and the UI is the same for logged in and logged out users (though keep in mind the logged out version is not entirely complete).
Mastodon's database size can often be reduced either through Postgres' VACUUM command or the pg_repack extension, the latter usually being more effective as a lot of the size is in index bloat which VACUUM does not touch. Mind that I do not recommend running VACUUM FULL unless you absolutely need to reclaim disk space on the system.
The new joinmastodon.org website delivered by @oakstudios is live (has been for a little while, actually, but I've been working on it still). I think it's the best it's ever been. Check out the branding and about pages too!