I've got one for grinding for stovetop.
It's good, the grinding action feels a bit light in relation to my old hand grinder, but you get used to it, doesn't take long to grind, and is consistent.
Had it for about 4/5 months, no issues so far.
Would recommend.
Is bigger than you think though..
Sounds like the Rhinoware one is not a big step up from the Porlex.
I've seen this
Anyone used one?