"Island in the Sky" is located just 30 miles away from Arches NP, so the two parks can be easily visited during the same trip. Compared with Arches, Canyonlands does not seem too impressive, at least on the surface. I am sure though that it is a much better place for backpacking than Arches.
Upheaval Dome:
Agnieszka:
Green River Overlook:
Grand View Point:
Mesa Arch: