Rab Ascent 700

Warm, lightweight, highly packable, roomy, designed to pair with a similar bag, wide temperature range. This sleeping bag is a desired addition to a backpacker's load list for at least 1.5 out of 3 seasons. No need to compromise temperature and sleeping comfort for weight any more.

When choosing a sleeping bag for backpacking it's a hard battle between warmth, weight, and price. Ideally a sleeping bag is very warm, exceptionally lightweight and packable, and costs almost nothing. But this will never happen of course. So a compromise must be found and for me the Rab Ascent 700 was that compromise when I bought it on sale for about 60% of a regular price considering using it during border seasons trips: fall and spring.

Warmth

The bag has 700 grams of duck down 650 FP insulation with EN comfort rating of -2°C/28°F.

I personally prefer down insulation to synthetic because from my experience it will serve longer without losing its characteristics over time. I used the Ascent 700 in late fall, winter, and early spring when the overnight temperatures were between -5C/22F  and +2/36F and I was warm wearing a single layer of sleeping clothes.

Of course the back side of the bag feels colder because it's compressed, so make sure your sleeping pad is warm enough for the season. Zipper has an anti draft internal baffle that eliminates a zipper cold spot.

Fit and Comfort

The bag comes in two sizes: Large and eXtra Large and for me being 190 cm/6'3" tall and 92 kg/203 lbs the XL size feels just right. It's long enough for me to be fully straightened and still have enough room in a hood for a pillow.

The width is enough to have some freedom for my elbows and knees and the foot box is close to the right size being just a bit too larger than it should be. The hood is large enough to fit a pillow and can be cinched down to leave just enough opening to breath through and remove any cold spots. A draft collar works well and almost cannot be sensed unless it's cinched separately from the hood.

Entry and Exit

Bag has a large metal YKK zipper (which adds a little to the weight but also is supposed to be very reliable) of 3/4 bag length that is long enough for easy entry and exit and almost never catches on material because of the anti snag design. 

Moisture

The duck down Rab uses is specially treated so it becomes hydrophobic and does not get wet and does not loose its insulation quality. 

In addition Pertex material that is used for outer shell is water repellent and can withstand moderate condensation with no problem. Though to be true I have no idea what would happen if the bag was fully submerged into water. I guess nothing good so it should be avoided. But during late fall, winter, and spring high humidity and rains I've noticed no reduction of insulation ability.

Packability

Very good. The bag comes with a compression sack that totally fits in backpacks' bag compartments of Osprey Volt 60 and Deuter Lite 45+10 SL. In addition the bag is relatively lightweight comparing to other brands and models.

Ease of Use

All the zippers work seamlessly and don't snag. But it could get awkward when trying to access the internal accessory pocket or close/open the top zipper velcro. When cinching hood and collar cords their drawcords become quite long and may get in a way inside the bag.

An interesting feature is an ability to zip two bags together into a single two-person bag. Bags should be of different zip orientation and YKK zippers are easy to reconfigure. In my experience such configuration is less convenient even though it may allow for sharing warmth because of: a cold spot along the back zipper; collar and hood draft in the middle; a crack between sleeping pads if they are not attached together.

In addition it's very useful that the Ascent 700 comes with a storage bag where it easily goes after every trip.

Quality and Final Conclusion

Quality of the materials and workmanship are high top. Overall I am very pleased with the bag and have high hopes for it to serve me well for many years ahead. Though I do realize that I would not have bought the bag was it not for the large discount because of a steep regular price tag.