I use it at work connected to a mac, it works as a numpad just fine regardless of the state of the numlock and none of the fn+ options work other than changing the lighting settings, which is fine. It would be nice if there was a heavier weight switch option.
After spending a month or two with this product a few issues became pretty apparent. The sound and feel are just..okay, barely feels like a mechanical, decent amount of rattle along with a hollow sounding case. The main problems are the lack of hotswap and it being wired. Not only wired, but mini-usb which is more than a little annoying. At $50 you can do a lot better for a macro/numpad nowadays.
It checks all the boxes for functionality, but some more choices for switches would be nice and the USB cord is an older style on the numpad side. Overall happy with it but didn't really shop around for alternatives at the price point. I'm not sure how much of a premium you'd have to pay for a full 5-star mech numpad, and it's definitely nicer than any membrane thing, so I think it's reasonable value.
If you need a numpad for functional purposes this will do the trick but if you're looking for something that sounds good and feels good you could do better than this one.
I'll admit my big complaint -- that it feels tall -- is mostly on me because I did not think to compare its profile height vs my primary keyboard, but it is always a bit jarring for me to go use it.
The other problem I have is that it's got a single, always-on light under the numlock key. It's bright and kind of obnoxious. I find myself switching off my keypad at night because my spouse and I live in a small apartment in a big city and it'll actually wake us up if we wander out to the WC in the middle of the night.