When I'm on the move, the 300 rarely gets above 65, and sticks around 60 of an evening. But as Steve says, Thanks to the huge rad it's really shifting some heat.

I'm not running a thermostat. The only problem here is that it takes a little while longer to warm up, so it means I have to annoy the neighbours as I'm blipping it up to temp. I never ride it away from cold (less than about 50 deg)