I originally purchased this jacket for hiking, and find it so comfortable that it is used every day. The liner is quilted with the Omni-Heat shiny layer on the inside. It easily zips into the outer shell and is held in place with a snap in each sleeve, along with one at the collar. The zippers are high quality, the collar is toasty around the neck, and the hood prevents any wind from getting to you.I love hiking with just the liner, and as long as you keep moving it keeps you beyond warm. Half of the time its mostly unzipped. Then if it begins to snow or rain, I can grab the shell out of my stuff sack and throw it on in a matter of seconds. The liner has nice deep pockets on the outside. The shell has outside pockets and one on the chest as well. Then on the inside, there is a huge pocket for goggles and a small MP3 player pouch that protects my android perfectly. One of my favorite features is that it has a grippy stretchy band around the waist. This prevents it from riding up as you move around.There are two things that did bum me out. The sleeves slide out from under the shell sometimes. This isn't THAT big of a deal, but kind of aggravates me when I have to tuck them back in here and there. Also, this jacket liner runs short. The grippy band is on the shell, so if you are wearing the liner alone and raise your hands to the sky.. you now wear a belly jacket. I understand why it is short, as it is designed to be worn with the shell.. but it only comes to the top of my belt buckle. If you have a long torso you may find it uncomfortable alone..Either way.. this is one of the best jackets i've ever owned. I think the Whirlibird II and III don't have the length issue and fixed the sleeve tuck problem. If you find it on sale like I did, you won't be disappointed..(By the way, the black jacket shell comes with a green/aqua looking liner. Beautiful and subtle enough color to wear every day)