If you have video-only content like a presentation you're fine. The moment you've got content with audio, like a movie, the AV sync issues are intolerable. I had one of the Microsoft adapters and I'd also see dropped frames and stuttering video. That was when I could even get the thing to connect. Apple's AirPlay isn't perfect by any means but it's a far better experience than I've ever had with Miracast.
> The moment you've got content with audio, like a movie, the AV sync issues are intolerable.
VLC media player allows you to adjust audio delay. Doing so can help combat the issue.
I used that adapter to watch a bunch of Game of Thrones episodes with no noticeable lag issues. But the device casting was Surface, so maybe it's just a case of vendor optimizing for its own products.