None at all - never used one, never seen one, never seen a use for one - other than perhaps on antique valve equipment.
ESR meters though are absolutely essential, on anything with a switch-mode PSU - that's basically where electrolytic capacitors fail - a scope is useful as well. Assuming the PSU is running enough for it to be tested, you can run the scope down the outputs of the secondary rectifiers - and spot high ESR capacitors by the high ripple on their rails - this is particularly useful for things like satellite receivers, where you would need to remove the PCB to test with an ESR meter, with a scope you can test with the board in place.