Never have understood why the air temp gauge was ever put on the bike in the first place. Your are outside on the bike, you know if it's hot or cold. The real "here's your sign" signal is that it isn't really reading "ambient" air temperature - If anything it is telling you the temperature between the cylinders, which is an indicator of nothing.
I would go with an oil temperature gauge and OEM to match up to the rest of your instrumentation. I have it on my winter "to do" list.