I've had an X-H1 since last October. I've used it both with and without the booster grip and with the 16-55mm, 10-24mm, 80mm Macro and 100-400mm lenses.
I'm no pro, simply a hobbyist but I do tend to knock out a lot of images, especially wildlife (birds in flight) and motorsport (so plenty of Continuous High frame rate).
I've kept the Camera updated with the latest firmware as and when it is released and I can honestly say that the camera freezing in operation hasn’t ever been an issue on my copy.
Loving the camera! I upgraded from the X-T2 and with hands like shovels the X-H1 feels great in my hand, excellent ergonomics (for me) and I especially like the feather-touch shutter release and silky quiet shutter mechanism.
I appreciate the IBIS with the 16-55mm lens, gaining some great lower light shots with a decent shutter speed.
My one issue is autofocus hunting and inaccuracy with the 80mm Marco lens and near subjects. Not too much of a problem because most of that work is done on manual focus or with focus bracketing. When focused properly the lens is tack-sharp and the images stunning!