Wi-fi has been buggy on OS X for literally years now. And each new major release seems to bring some new pain point where it refuses to turn on, refuses to connect, doesn't transmit data... and on and on. There's no way Apple can't know about this - it must drive their own employees crazy. Yet, nothing gets done.
If I were in the market for a new laptop right now I'd be taking a serious look at a Surface Book - it's the first thing I've seen that looks like it could rival a Macbook in the hardware department. Sadly, I'd have to do a lot more research into getting a decent POSIX environment set up on it before I could take the plunge.