My comment is probably biaised because i’m part of PieFed team (translation, wiki, idea, issue…). I hope more devs will join us :)
On the moderation side, features, PieFed reached a good maturity. We have good tools against bot, and other tools that improve our community. I dunno how other fediverse software handle that.
On UI, we are fine, there is a bottom nav bar, a search bar it works well on mobile. It is visually clean except lengthy community and menu. There is room for improvement compared to Lemmy and Mbin. It will be adressed soon :)
The main thing that most Lemmy users will miss are mobile app because PieFed API are not complete or app are in developpement. Also that’s because PieFed improve and grow at a very fast space.
However, you can use PWA (progressive web app), it works well. Also Lemmy v1.0 will catch up some piefed feature.
If you are interested, you can try it on yunohost or create an alt to try it. :)
Good question, i will test it. For now the only gallery post i see are from Mastodon. :)