I struggled with poor fonts in Firefox once I switched to Arch. Upon finding Infinality, I gave it a try.
It worked really well, so that fonts in Firefox looked great once again, very readable, etc.
My only complaint was in LXTerminal, since I had been using “Anonymous Pro” there for my console font. This became totally unusable. I think it had something to do with it being a bitmap font, but after much searching online, I couldn’t tell for sure and couldn’t fix it.
Thus, I switched my console font to ProggyCleanTT for now. It is OK, but I don’t like it as well as Anonymous Pro (maybe because it is different).