Hario could be more popular because Hario, not sure though. I’ll ask said coworker if he has experience with other devices (pretty sure he dailies a V60).
As for faffery levels: yes, if that is your cup of tea (ha), that slightly changes things of course. ;)
From the look of things, yeah, the OXO device looks similar enough to a Gabi, just a different filter type and a different (bigger) size. If there’s a disadvantage to the Gabi, it’s that: it’s rather small, so unless you’re doing single cups, you’ll have to pour in a couple of rounds, making sure your bed doesn’t dry out in the meantime, etc. It won’t be a problem if you do single cups, so I suppose that’s what it’s primarily aimed at. Oh, and the type of filters differ, of course, so if you have a strong preference there, that might dictate the dripper/drip-assist you can use.
Either way, yes, the OXO looks to be the same kind of thing, good to hear it works well, too!