I've found HN pretty easy to use with both Chrome and Firefox on Android, at default zoom, with my own pocket supercomputer.

Sometimes I manage to hit the updoot or downdoot buttons incorrectly, but that error happens so rarely that I'm amazed at my success.

Responsiveness is very good, as well. Loading is lightning quick in all but the very worst network environments.

It's not perfect by any means (the text box I'm writing this into really should be resizeable, for instance), but it's not bad at all...for me.