I've written a log viewer/analysis toolkit for dRonin, a flight controller firmware for quadcopters and other aircraft, which uses pyqtgraph. I love it-- it's really awesome!
There's a couple of features I'm using from current pyqtgraph development code-- infinite line labels and pyqt5 support. It's really nice Pyqt5 has wheels available.
Can current dev code get released sometime soon? It behaves pretty well from what I can see-- no obvious regressions.
My main alternatives are to bring in pyqtgraph's code at a trusted revision as a submodule (yucky), or to use requirements.txt which would cause a development pyqtgraph to get installed systemwide... neither is really awesome.