In terms of XCadey support, I'm not particularly convinced by the accuracy of the product, but they did replace mine that failed (a few days crazy readings followed by complete failure to activate or charge). It did take a while - some on me some on them (I started comms via the AE vendor) - they asked for multiple videos (which did take me ages to get around to record and send) and kept asking me to connect it to the app and do a screenshot of the calibration number, even though I told them it didn't work. In the end I did have to get a bit shirty at them when they asked for yet another video, and they sent me a new once once I sent the bad one back (to PL from UK) - so replacement cost about £10.
I have been using the new one for a few weeks - installed the latest FW (not the beta). It's believable on the face of it - only done 1kw type sprints at relatively low cadence thus far, and the ~200w Z2 reported after seemed reasonable. But I am not doing detailed testing like Shane (at best I'll be able to toss it on a Neo 2T at some point), so I'm glad he's validating these vendors' accuracy claims (also glad I'm not the one having to sprint on the small ring - that frightens me for some reason!)
As noted, the new app doesn't have the offset field anymore. They do have the BT connection signal strength, which I don't think they had before, very useful ... :-)