I was in the same boat, and I also now swear by the MX Ergo over the M570/M575. I have two complaints with it that (neither of which seems to be addressed by the MX Ergo+): the thing still charges with micro-USB (not a deal-breaker, but it's annoying that I need to keep an adapter or cable around for that one device), and that it's stuck on BT 3.0 (I'd prefer 5.0, as running trackball+keyboard+audio over BT from my old work laptop was enough to cause drop-outs, and 5.0 helps mitigate that).