Land asap, or dump fuel??
My 2 cents worth.
It depends on circumstance. If the remaining engine is operating normally, I would definitely dump fuel before landing. A Vref20/flaps 20 landing at or close to MTOW will be of the order of 175-180 kts. Not a good situation with only one reverser working.
But, if there is a compelling reason to land sooner - fire - I would land ASAP!