TL;DR: The mic itself is fantastic if recorded separately into a recorder. The wireless system is poor and compresses the audio signal in a way that makes it unusable.
For some context I am in the video production industry so I was able to test this mic more thoroughly than most.
I compared the mic itself to a Rode smartLav+, but unfortunately did not have another wireless system on hand to compare its to.
Overall my issues with this system come down to what I suspect is wireless compression from the transmitter/receiver. On both mics I used with the setup the audio came out crackly and 'digital' for lack of a better word. This can be heard in the first impressions video example I've attached.
Once you record the included lavalier microphone without the transmitter/receiver though it sounds fantastic. I used a Tascam DR-60DMkII for these tests. I actually preferred the Maono Mic's sound to Rode's smartLav+ which is a $70 lav mic by itself with no wireless system. For $60 you get the great mic and a quite subpar wireless system, but it appears Maono also sells lavs by themselves for cheaper so I'd recommend going with that and a separate field recorder unless you desperately need a wireless setup.
In other good news, the accessories and general build quality of this is wonderful. The kit includes a rubber protector with a nice study belt clip for the transmitter, a lengthy charge cable (Micro-B to B) that splits into two connections (great for charging both ends of the wireless system), and a really sturdy clip for the mic itself. It is also packaged quite nicely and securely and even includes an extension for the receiver's 3.5mm jack for devices that need it. I do wish this was a cable extension and not a hardline jack though, would provide more versatility.
Other nitpicks:
I wish the cable on the mic were like a foot shorter. I'm 5'11" and I had tons of slack on the cable with the mic clipped to my shirt collar and the transmitter clipped to my waist.
The velcro strap around the mic is nice in theory, but it just gets in the way in practice. I have the mic wrapped around the transmitter which is plenty for cable management when not in use. Add a way to remove the strap without damaging it or get rid of it altogether.
I wish the kit came with a carrying case or pouch. There's a lot of small bits and bops that will easily get lost without some way to keep them together.
I would not buy this if you care about the quality of your audio through the wireless system. If you'd like to overpay for what I suspect is a trimmed down version of Maono's $20 lav mic then go right ahead!