TL; DR - Order took 2 months to complete; shipping information was incorrect/incomplete; customer service is non-existent.
I ordered 2 masks and several filters mid-April, with an advertised 10-14 day estimate. After a week I got 2 shipping notifications, each containing different portions of my order (first was masks, second was filters) but both had the same tracking number. This package sat in a "Departed Shipping Partner Facility, USPS Awaiting Item" status in New York for the next 5 weeks with no updates, after which point it jumped to California; it delivered in a few days from this in early June. However, the package contained only 1 mask and the filters (contents not matching either shipping email). I also received a notice from the USPS that I had a package coming from some other company I've never heard of (originally Yanwen, now showing Pitney Bowes), which also sat in the same status in New York before it finally arrived at a real post office (this time in Indiana) for delivery; this contained the missing mask (again contents didn't match any shipping notification from the company). I also experienced the automated ("fake") email reply from their customer service, but never any real reply. The masks themselves are decent though.
While I did finally receive my complete purchase (almost exactly 2 months later) and am reasonably satisfied with the quality of the product (could be better, could be worse), the overall customer experience was just bad.