I've had four of them. 3 working perfectly, 1 has an issue, where the hour hand gets occasionally loose, but only when you use the independent hour hand setup.
It again works perfectly when you set the time only from the hack position. The movement isn't going to die or anything, it's a genuine ETA. The problem with this modification is the badly constructed hour hand transfer gear/fork, which can cause slippage. And when the hour hand gets loose you can "attach" it again when you roll the minute hand around the dial for ca. 24 hours. I don't know the technical explanation for that, but it works for both me and bklm1234 who owns a chs GMT II as well.
The date change on the old chs movement follows the GMT 24h hand, not the hour hand. But if you set your 24h hand to follow your local time the date change is no problem, either.
But then again, this is supposed to be a new, improved correct hand stack modification where the date change follows the hour hand. That's what Angus told me anyway.
Too bad I'm not too crazy about this ceramic version, gen or rep. I doubt I'm going to drop $400 for it.