Note the below comments on this used lens. Obviously I'm concerned about the special note in the last paragraph red type. Should I have any concern with this?
Barrel - almost no wear visable - somesmall paint chips near lense mount - see photo- a few skuffs and some paint wear also where hood attaches. Dent in front rubber - very slight - see photos. - Focus smooth - IS also relatively quiet compared to some I have seen and used. Lens Code - UT0212 Lens Serial #286xx
Note please - lens not smooth to rotate when mounted on tripod - seems to be rough - might need servive on tripod mount if it bothers you.
It's probably another sign that the lens has been mishandled. It should rotate smoothly within the tripod mount, so either it's been subject to a lot of wear or it's been slighly damaged by a fall or bump.
In itself a stiff tripod mount rotation is no big deal, it's more of a question of how did it get that way.