I've always loved sync, but just checked thunder. Almost immediately uninstalled as on default settings the ui is way too cramped and lacks contrast with all posts blending to each other. Very hard to read for me. I guess you could make it better by fiddling with the settings, but I just went back to go sync where it's already very good on default settings and I was able to make it perfect for me just by changing a couple of settings.

Edit: downvote as much as you want lol, it's just my opinion. Good to know that Lemmy is just like reddit with opinions ;)