Well, so far very good. A lot of what I currently like to do are heavy blanks in the 40# range. So the lowest belt setting gets me thru the heavy rough out and then jumping up just one belt setting gets me plenty of range for all my fine roughing and finish cuts. With a big blank I usually top out in the 600 rpm range, especially if the blank has some internal mass that is out of balance.
I've had the lathe turning at 40rpm (lowest belt) for a long sanding session and motor stayed cool.
This motor is rated 2:1 (900 rpm motor shaft) for constant torque - I take that to mean heavy roughing, gouge always in the wood taking lots of material really fast.
This motor is rated 5:1 (360 rpm) for variable torque - which I take to mean a lot of what we do with a lathe, taking finish cuts, sanding, etc. Most of the time I'm not putting a lot of load on that motor. It's not having to lift a heavy load up a conveyor belt, etc.
So time will tell, but so far I'm one happy camper after spending some time jealous of my friends with VFD. And I'm absolutely sure this is what has been holding me back from doing some world class turning - yeah sure.