Which is warmer, the Nuuk or the McMurdo?

The McMurdo's down fill generally feels warmer in dry cold. The Nuuk's synthetic padding is close and keeps insulating when damp, which down does not.

Which handles rain better?

The Nuuk. Its 10,000 mm membrane and storm hood shed steady rain; the McMurdo's 2-layer shell is built for light precipitation and dry snow.

Is the Nuuk worth stepping up to over the McMurdo?

If you are outdoors in wet weather, yes. For dry city winters, the McMurdo's warmth and detachable hood are enough.

Both are durable. The Nuuk's synthetic fill does not clump when wet, while the McMurdo's Velcro and down need more care over the years.

Can I layer a sweater under either?

Yes. The Nuuk's regular fit leaves room for a midlayer; the McMurdo runs roomy too, so size down if you want a closer fit.

Which is better for hiking?

The Nuuk. It is cut for movement, has a fixed storm hood and more pockets; the McMurdo is a street parka.

Fjällräven Nuuk Parka vs The North Face McMurdo Parka

The Nuuk Parka is the better pick for wet, cold, active days: a 10,000 mm waterproof shell, a storm hood and 11 pockets make it a true winter workhorse, and its 62 ratings average 4.8. The McMurdo is the warmer, softer choice for dry city cold, with down fill and a detachable hood, but its 2-layer shell and Velcro closure are less weatherproof. Both are heavy, bulky parkas; the Nuuk is the more versatile outdoor jacket, the McMurdo the more comfortable street coat.

Choose the Nuuk Parka if you face rain, sleet or wet snow and want one jacket for hiking and commuting.
Choose the McMurdo if you want maximum warmth for dry, cold city winters and a hood you can take off.

Prices

Fjällräven Nuuk Parka: $374.50 at eBay (last seen Nov 4)
The North Face McMurdo Parka: $314.49 at eBay (checked today)
Difference: the The North Face McMurdo Parka is $60.01 cheaper than the Fjällräven Nuuk Parka at the latest prices (Nov 4 and Nov 9)