That route is billed as a 'Mini Cabot Trail', but the 'trail' part of it really is pretty 'mini'. It's an OK change of pace though, and really doesn't take that long. The asphalt is in reasonable shape.
If you get a few minutes, stop at the Arisaig fossils site. It only takes a 1/2 hour or so to walk down to a pretty weird beach with neat fossils. The Cape George harbour has an interesting sword-fishing exhibit and there is a chip wagon if it's lunch time...

Cape George

Arisaig 'Silurian' rocks...