Sync is pretty good but its font options are awful on my phone. If I set the comments font size to “huge”, it’s still smaller than e.g. the clock in the notification bar. And then it’s an unreasonably large jump from “huge” to “header”.
It needs a simple font size slider instead of preset mystery values. As it is, it’s just uncomfortable to use.
Not sure if Sync for Reddit had the same problem since I used other clients more.