I was using Thunder last week until Sync’s open beta got approved and the User Experience and the interface of Thunder is nowhere near Sync. It’s a night and day difference, and a difference that would have made me use Lemmy less and less.
Thunder is like a month old - it’s still growing and will continue to improve with the community’s help :) if you think anything could be improved, definitely shout it out on the GitHub page!
I understand that it’s new, and it is definitely the best FOSS Lemmy app out of the dozens that I used. But it has a very long way to go to achieve the same level of User Experience that Sync has. It’s not even close and I don’t think anything bar a major UI/UX rehaul could fix that.