Anyone have any experience with these ?

I’m interested in getting a down - 800 fill for either 30 or 40 degrees F, and use it within a synthetic overbag for colder temps
Any comments ?

I love them.
I have a 0 degree, a 15 degree, and a 25 degree.
Used to have a -20 as well, but didn’t see enough use.
I have used a synthetic quilt system for my warmer temp bags.
Often something like a HPG Sarape or Thermarest Honcho Poncho.

Ed-T : Looks like th bags you have cover the cooler temps directly. I was looking to combine a 30 or 40 degree down bag as a liner within my 20 degree wide synthetic bag.

It is wide like me, so what I’m really wondering , is
how does the super spiral stretch system work for you ?

Is it a gimmick, or does it provide some stretch for a larger person.
Can you sleep on your side comfortably in it ?

I intend to put mine inside a wide synthetic overbag in cooler temps - Fall & late Fall hunting ,
As well as early season by itself,

The stretch really does work well. Conserves heat yet allows for movement.
I have paired a 30 degree down quilt with a 45 degree synthetic quilt or my Honcho Poncho to sleep well at around 15 degrees.
I have quite a bit of Mont-Bell gear and it has all been top quality and has lasted for many years with some hard use.

I should add that I am constantly tossing and turning at night so the Stretch bags or a quilt is what I have found works best for me.

A big +1.

I fight a bit of claustrophobia, and the stretch sure helps with the tied up feeling in a mummy style bag. Nothing like waking up in a panic in the middle of the night. I have a 0 (Red) and I think 30 (Green) degree bags. Had them for years so can't remember the exact numbers.

Thanks All for your responses on this topic.

The Mont Bell Spiral Hugger bags seem very innovative for keeping it close fitting , but providing room for side sleeping.
For summer, I would be using it for bike touring, and light backpacking. Later in the season it would go inside my wide synthetic bag.
Hopefully not too restrictive.

Thanks

another big +1.

Super Light, and room for tossy / turny big dudes that don't like the constricting mummy bags so much. I've had my 15 degree for 12 years and still holding up well ... (2 weekish hunts every year + the occasional sleep in the car / camp trip). I've been good from 6 degrees F to 40F and adjust with wearing long underwear in the colder temps where i'm in a Tipi and have a good pad with good R rating … if I'm cold I close the head and breath inside.

Anyhow, the big differentiator here is the stretch which gives awesome size/weight ratio and let's you move inside the bag.

The outer material is not the most rugged, but if you take care of your bag, it will take care of you.

Had mine for 7 years now I think. Been very happy with it. Love the Stretch. Toss and turn ability.

Thanks for all the constructive comments !

I appreciate the suggestion that a pad with suitable R factor, and a wide quilt may be the answer for summer temps down to freezing, or a bit below.The more I read on quilts, the more I like that approach for the freedom to toss and turn

Below freezing, I like the coziness of a lofty down bag. I just find that mummies are a tad confining for my active side sleeping style.
Unless they are quite wide, or barrel cut they can be too restrictive. My wide mummy is a synthetic that i’m Hoping I can use a 30 or 40 degree down hugger as a liner , for layered sleeping in cold temps. And of course as a lightweight packing summer bag.

Again, I appreciate all of your insightful comments.