I loath the font size of the subjects of posts in my feed. It's the opposite of sleek. Huge and bold regardless of anything I toggle. I can't find a way to change it and it puts me off. Al my font sizes are set to small, and the feed is compact, so seeing it huge and bold is just off putting.
I've kept with WefWef/Voyager for that reason alone. I come back to see if try here are more options, but it hasn't happened.
Otherwise it seems great.
Notice the gap in disparity between my name at the top, the font in the bottom row and the posts. I get it won't all be the same, but I also tried to show a post with not aton of text being in 5 rows.
Now compare to Voyager the same-ish posts...
To me, it's much cleaner and closer to my system font size. Not the end of the world, but when just scrolling through posts irks me, I look for alternatives. Though I did find a few other things I liked while figuring out how to reply and post images.
At the end of the day, I'm reasonable. People like what they like and tend to stick to that. I found WefWef/Voyager fist and it felt and looked like Apollo (font size and all). Then I found Memmy, so that might also play into it.