Had a look at iosevka - it definitely seems nicer than many of the others, but it still feels too vertical when compared to DejaVu in my opinion. Is there something that sold you on it?
I've also switched to iosevka after many years of dejavu sans mono. I really like the brackets of iosevka, and its italics. I also appreciate the customisability of it, and the fact that the font itself is in some ways built rather like Computer Modern via METAFONT (and that it uses a Lisp-like language to do so).
Well, it certainly is more vertical. The increased x-height allows it to be readable at small sizes (and fit more horizontally) which looks great in the terminal and editor, but maybe a bit odd on the test page.
Well, a week later and I think I'm a convert. I didn't like the look at first, but after using it in my IDE and actually typing with it, it's quite nice.