As far as fill i have found that Thermic micro > Polarguard Delta > Primaloft. I didn't do much research into the effects of primaloft except that polaguard delta out performs it in loft retention 50% instead of 25% warmth to weight, primaloft is lighter but polarguard delta gets more bang for your buck and cold spot protection. It's variable laying technique and ability to stay together prevents cold spots. However, Thermic micro basically does everything polarguard delta does, better. It also has a surprisingly down-like feel compared to most synthetic because it's not laid in a woven sheet-like format. It almost looks like a bunch of twisted spaghetti noodles inside the shell, which further prevents cold spots and feels softer and retains more heat, like a down bag. I was comparing the MH ultralamina 15 degree sleeping bag to the North Face Cat's Meow 20 degree bag. The weight savings, warmth, and durability make this decision an no brainer after a little research. I'm not familiar with the two bag's you mention however, the Mountain Hardwear offers a nylon 20d ripstop with a DWR coating while the cat's meow is a polyester taffeta blend. The rip stop is more durable and repels water better, also the rip stop employs the box containment method, if it does get ripped the rip will stay confined in the boxes that it ripped preventing tearing. Also, it's welded seems prevent cold spots and water from entering the fill. The MH ultralamina was designed for wet climates and can repel precipitation and ///some/// puddling. I put it in a sink full of water and it did penetrate the shell, however within an hour it was cold/damp (not dry but most of the water had drained) and within three hours it was bone dry. However, it's a synthetic fill so even if it does get wet you wont loose it's insulating properties. Also, both of these bag's have vaulted footboxes which allow your feet to rest normally, however the ultra lamina has dual 1/3 zips meaning they only zip 1/3 of the way down, while the cat's meow has a full zip on the right side. The 1/3 zips are great on a cold night or if your cooking, reading, whatever, however if your warm it's nice to be able to unzip totally and let some air in. The MH ultralamina employs a face gasket and tailored hoot which offers a tight seal keeping body heat in and cold air out. The MH ultralamina is the no brainer for me as it compresses smaller, is lighter, warmer (yes i know one's a 15 one's a 20) and is more durable/water resistant.