Montbell Ultralight Thermawrap or Patagonia Nano Puff

The Thermawrap uses 50g/m2 of Exeloft insulation and the Nano Puff uses 60g/m2 of Primaloft One, which is a superior insulation, so the Nano Puff is the winner in terms of warmth. Having said that, with so little overall insulation in both garments I'm not sure the difference would be very noticeable, if at all.

Having tried both, I prefer the fit of the Thermawrap. It has a little bit more of a slim fit, while the Nano Puff seems very boxy to me. If you are carrying a little extra weight, you might want to opt for the Nano Puff.

Finally, different versions of the Nano Puff are much more readily available than the Thermawrap. With the Nano Puff, you can easily find 1/2 zip pullover, full zip jacket, and full zip hooded versions. With the Thermawrap, you're probably only going to find the full zip jacket. I've seen some hooded versions floating around (try googling 'ultralight thermawrap parka'), but I'm pretty sure they were discontinued in 2010-2011 so they're few and far between.

You can't go wrong with either and they're very comparable, so if weight or money is the biggest issue go with the Thermawrap. If you want a specific version or want as much warmth as possible, the Nano Puff might be a better choice.

I own a Thermawrap, but I bought it before the Nanopuff was released. It's hard to argue with Patagonia's repair / replacement policy. Buy a Nanopuff, use the hell out of it, and when you damage it get it repaired / replaced…

I don't like Nano Puff. Just sold my brand new jacket for cheap in CL (since i'm not a member here.)

It was light, but gave little warmth. I like my similar Stoic jacket (mid layer) better. Stoic has better fit, has nice cuffs that keep warm air inside, packs same and cost me half of what Nano Puff did.

50 or 60g/m insulation aint that much for camp …

i think that the nano is noticeably warmer than the thermawrap. For the same weight though you can get a rab xenon which IMO is the best jacket of its type + it comes with a hood for the same weight as the patagonia pullover. Can be had for a reasonable price on sale.

I own both jackets, too and I can 100% second Kenny R. The Thermawrap has become my default insulation jacket because it is the more lightweight of the two and I have abused it for years now and it still holds up. I will definitely buy another Thermawrap when the old one finally dies. I consider it one of the best lightweight products I own.

I only use the Nano Puff in town because it is much wider than the Thermawrap. But as Kenny R has said: You cannot go wrong with eihter one of them.

I found the montbell products to be short in the arms and torso which for me is an issue as i am long armed and torsoed. The patagonia are longer in both arms and torso although i would agree that they are more boxy.

Find the nanopuff on sale for at least 50% off if you are buying as patagucci retail is not worth it. At 50% off they are very good value.

I own both, but I prefer the Nanopuff. For one thing, it's noticeably warmer (as someone above mentioned, it has about 20% more insulation per unit area than the Thermawrap. Also, the Nanopuff comes as a pullover, which I have, that saves you a bit of weight on the zipper. I almost never wore my Thermawrap unzipped anyway. The fit of the Nanopuff is slightly looser (I have a medium in both), but I scarcely notice the difference.

One more benefit of the Nanopuff: because it's puffier than the Thermawrap, it makes a better pillow!

The only time I use my Thermawrap now is for 3-season hikes when I'm not expecting temps below 40. Anything below that, and I bring the warmer Nanopuff.

this doesn't directly answer your question but, for 3 season use in the rockies, I'd probably grab a down jacket. More warmth for less weight and it shouldn't be hard to keep it dry in the rockies.

Montbell and Patagonia have offerings that would work well.

I agree with Ben, if it is going to be for 3 season use, I would go with a lightweight down jacket. There are quite a few options.

Sticking with the OP, I would suggest the Nano. The MB jacket is lighter because of no hood and lighter shell material.

Yes with synthetics you can tear the shell and have no worries. With the MB, you tear the shell badly by accident, you're buying some duct tape. With the Nano, you tear it badly (your fault or not) you're getting it either repaired at no cost or replaced.

I might still have the photos somewhere, I will check. But true story…climbing this past spring in Indian Creek. My drunk buddy had his Nano tied around his waist. None of us noticed that he was standing with his back a little too close to our fire. Nano went up in flames. When we got back, we called Patagonia to tell them the story, and to possibly try to get maybe a 30% coupon code toward a new jacket for being such a dumba**. After the customer service guy composed himself from laughing so hard, he told him to mail the jacket back. A week later he had a new jacket and a note from Yvon saying that he missed those drinking nights by the fire with his buddies.

I have owned both, and I find myself using the Nano Puff much more often. With a 1/2 zip pullover the extra weight isn't too much, and I find that it is noticeably warmer.

Just be patient and wait for a 50% off sale. I recently just grabbed mine for $75 shipped from Backwoods

I paid 90 for my nanopuff full zip on yr end closeout. In L it weighs 12oz, the Thermawrap in L weighs 10oz, and it is tighter fit, it isnt as roomy. If I bought the thermawrap, I might have to size up to XL, so the wt diff would actually only be a bit more than 1 oz.

Everything Ive heard and read says the nano is warmer.

I wear mine all around town all the time, every day sometimes when its cool. Its a piece of gear I definitely get my $ out of. Of course I have black and not one of the ..er..interesting colors..that some buy on closeout, that may not lend themselves to around town wear without drawing looks. If it wears out, Ill buy another, even at full price.

The amount of insulation you need depends on what you are doing. If you sit motionless, you dont make any heat and you cant bring enough insulation to keep you warm. Ive frozen deer hunting in 40 degree damp weather after 4 hrs sitting motionless when heavily insulated.

My Nano layered with my 100wt fleece, and long sleeve wool baselayer keeps me warm with light movement around camp down to about 30 or so. But you dont sit around the campfire for 3 hrs and expect to be toasty. You eat, then get in sleeping bag.

Given how low the iclos on synthetic jackets tested in the lab, I'd just stick to down.

downs great, but if you have a down bag where you might get wet, either thru repeated nights of condensation or rain or falling in a water crossing, its prudent to have your insulation layer be something other than down.