These two quilt designs share a number of important features, while also appealing to each their user group.

Common features:

ETC, differential cut, mummy style permanently closed foot, advanced baffle design, properly filled down chambers, real life size measurements.

What you get with the Arc UL that is NOT present with the SULO:

Beginner friendly

Draft collar at the top opening

More size options

Roomier fit

Easier vented foot section

More fabric choices

What is unique to the SULO:

Lower weight

Lower price

Snugger fit

Longer closed foot section

Less beginner suited