I have one of these, but I've never been able to get good results with it. The screen doodad that is supposed to sit on top of the coffee grounds always flips up and pushes all of the grounds to one side. The resulting cup ends up bitter and acrid, even with condensed milk. I'm not sure if I'm doing something wrong, or if there is something wrong with my brewer, or if everything is working as intended and I just don't like it.
Ah, mine has a threaded insert that comes up out of the coffee bed and the bit that sits on top the grounds screws onto it; no flipping. I did screw it down too tight on one attempt, which jammed it up and the water didn't flow through.
I think with revisions to grind size, ratio, and water temp, I can make a decent cup. Fewer grounds got into the cup than what I was expecting. And the s&c milk probably covered up some sins.