The 400s has a silver coated reflective side for when it's hot out. It stays noticeably cooler underneath than a normal tarp.
It reflexes away the UV rays. At night put the reflective side down and it reflects your lantern, with the added bonus of confusing the bugs.
On cooler days put the other side up and it will absorbe more heat from the sun.
It's also very waterproof and stands up well to high winds. Cooking under it when it's raining is a big plus.
All your gear stays nice and dry. Plus there's plenty of room to relax without burning when the sun is at it's peak.
Many people put their tent halfway under the tarp when camping so acts like a large vestibule.
It does require additional poles and support, so check out the Luxe range for options.