Overall these pants are great -
Pros: Lightweight, they look and fit great, they are very breathable with little to no moisture accumulation. The full-length zipper allows for super simple and clean on/off, and the fly makes taking care of business simple.
Cons: The windproof flaps on the interior part of the zipper almost always catch unless you pull the zipper out away from your leg, then up.
Pros: Simple design, lightweight, easy to find mantles. When operating at lower elevations this thing puts out some intense white lights. Startup is easy and reliable.
Cons: Despite some trouble shooting and tinkering I couldn't get mine to put out more than a matchstick worth of light above 9,000ft. Not sure if this is typical of all units or just mine. Flame up occurred very easily with only minor movement. When you use the lantern you'll need to keep it on a stationary level surface - very small amounts of tilt will cause the mantle to become unstable and the unit to flame up.
Without the light feature the attic is functional. It provides plenty of pockets for organization, and lots of shelf space to stash miscellaneous items. The lights are stuck onto the attic, and are simple plastic encased LED's that run on small watch batteries. There is no information included with the packaging that tells you if the batteries are replaceable or not - I had to contact Sierra Designs twice to find out that they are. However, good luck opening the case without destroying it. My recommendation would be to stick the lighter, less expensive standard attic.