RSSI: -48
Noise: -87
Connection is solid.
I have to say-- I'm confident that what your asking for will tell you a grand total of zero about whether or not your card/adaptor is having issues.
WiFi signal strength includes so, so many variables, that short of testing in a very controlled environment (or controlling for all factors but multiple versions of the card/adaptor in the exact same system in the exact same location at the exact same time)... you really can't figure it out this way.
I could move my system 2 feet over and get totally different numbers. I could have the washing machine on (as it is right now) and get different numbers. I could be transferring photos over USB 3 and get different numbers. My neighbor could turn on his TV and I'd get different numbers.
BTW: I installed the card + adaptor listed here and it works pretty well. Wifi worked immediately. Bluetooth was a bit finicky getting the first pairing to my keyboard and mouse (Apple). Took a reboot or two and some patience. Continuity seems to work, but it's a little buggy (as it is on real Macs too). Keyboard works at the bootloader! I haven't gotten the keyboard to work in order to enter BIOS, but that might also be a key issue.
I do wish I had a longer power cable for the Bluetooth portion of the card for better routing around my GPU.