As I mentioned before, there seems to be wide range of how any fan clutch acts. I see differences in the stock clutches right out of the box, some engage harder (louder) and pull more air.
With the ZJ clutch, I ran it for six months, starting in the summer and removing it in that winter. It worked great for that summer's wheeling trips.
With a 425 weekly commuter mileage, driven at night when the traffic was light, I was able to track fuel usage before and after the ZJ clutch, there was a drop in mileage and, like Ehall, on very cold winter morning, it took forever to warm up.
And yes, the thermostat was a 195 degree.
Once the stock clutch was reinstalled, it warmed up normally . Having the fan partially engaged all the time provided too much cooling air when the engine was cold
YMMV