Is it really worth riding this supplementary bus service instead of the shuttle? SMB5075L on E31

The E31 or express 31 is a supplementary bus service for the reduced services on the circle line, express 31 is infamous for being super slow due to its very laid back schedule, I for one experienced how slow it was when I checked the shuttle out, so is it really worth it riding this bus service or are you better off continuing your journey on the circle line which waiting and the ride would be a lot more faster?