Nunatak

I've got the Arc Alpinist and Arc Specialist, if I had to do it over again, and only buy one Nunatak quilt, I'd go with the Arc, but would get the Epic fabric, and 2oz of overfill.

If you want a quilt just for Summer usage, the Specialist without any overfill would probably be fine even in temps down to 35deg.

I'm 5'11" and the large quilt is fairly big for me, and the Medium fits just about perfect, unless I lay on my stomach with feet fully extended, which then stretch into the bottom of the foot-box. On my back or side, the medium quilt fits well.

They are both 32° F rated and there's only 1 ounce of weight difference between them. The big difference is in the circumferences. How big around are you and how much do you roll around at night? That should tell you which you need.

The Arc Specialist is just a wider version of the Arc Ghost. It adds $34 and 1 ounce.

Ghost = 46" shoulder, 43" hip, and 34" foot
Specialist = 55" shoulder, 45" hip, and 38" foot

WM Summerlite = 59" shoulder, 51" hip, and 38" foot and weighs 19 oz, 1 to 2 oz more than the Nunataks.

Bob,
If I remember correctly the Specialist uses 1.75" baffles and the Ghost has 2". I believe this is to help control the down in the wider width cut of the Specialist. Both quilts are spec'd with 8 oz of fill as standard. I'm sure that a buyer could have Tom use 2" baffles and an overfill to more closely mimic the Ghost.

If you want a lighter quilt, Tom will customize your quilt. I had him make me a Ghost with 2 oz less down and shorter baffles. With insulated jacket, pants, and mid-weight long johns I've had it down to just above freezing and was amply warm.

It's perfect for summer – not nearly as hot as my other bags. Mine weighs 12.7 oz in a size medium with Pertex shell.

It's all going to come down to your physical size and how you sleep. I had my Arc Specialist made in a 6'1" length since that's how tall I am. I went with the Specialist for two reasons… firstly I side sleep which takes a slight bit more width to cover and also I move around, and secondly I want to use it well into the shoulder seasons over the down parka and pants I already have. With 1oz overfill and using the 0.8oz Pertex it weighs just 17oz. For strickly summer the Ghost with 1.75 (or 2") loft and no overfill would probably suffice, and depending upon fabric would be very lightweight.

I'd go with the arc specialist. The extra width will make a ton of difference in ease of use, especially when using it in colder conditions.

I've got a BPL arc X (it's essentially the same as the arc specialist) and an old Golite Fur 1 quilt that is 46-48 inches wide and it's much more diffilcult to use due to the narrower width.

Thanks for all of the responses. I too am a side sleeper. It appears like the Specialist would be the better choice due to being able to move around more comfortably.

Robert, I encourage you to work with Tom Halpin, Nunatak's owner, to design the bag that suits you best. Nunatak is a custom shop, it won't cost much more to alter one of the standard designs to fit your shoulders or other idiosyncracy. He knows what he's doing and he likes getting things just right for the customer. Sleeping bag is no place to skimp, and Nunatak is a large investment.