Big Agnes – The Mother of Comfort. That’s the tagline, that’s the promise. I’ve tested tents, pads and sleeping bags from the Steamboat Springs-based company before, but never one of their special ‘Big Agnes System’ bags. Enter the Lost Ranger 15 and the Q-Core SLX. Respectively, great products. So what happens when the two come together like they were mean to?
Big Agnes Lost Ranger 15 Features:
- New design improves connection between pad sleeve and bag giving the contour shape a roomier sleeping space without adding bulk
- Design improves useable interior space and bag drapes over body
- Free Range Hood increases ability to lift and move head even when zipped
- Vaulted foot box creates more wiggle room for your feet
- Stretch fabric panels on the side of the pad sleeves accommodate different pad thicknesses
- Stretch fabric panel beneath hood creates a designated pillow pocket
- One hand hood synch cordlock is simple and easier to use
- Zipper Garage stores zipper and eliminates Velcro
- DownTek™ water repellent down insulation – warm, dry and environmentally friendly
- Integrated full pad sleeve. Never roll off your pad again
- No-draft collar, No-draft wedge, No-draft zipper
- Weight: 2lb 15oz
- MSRP: $279.95
Big Agnes Q-Core SLX Sleeping Pad Features:
- Built-in advanced heat reflective technology
- Antimicrobial treatment inside the pad prevents microorganism growth
- Minimalist I-Beam construction reduces weight and provides consistent stability and comfort
- Quilted top provides a cushioned pillowy sleeping surface, as comfortable as your bed at home
- Larger outer chambers keep you comfortably cradled in the middle of the pad
- WRM HL™ – Ideal for sleeping pads – this durable, high-loft synthetic insulation provides exceptional warmth with minimal weight and bulk
- New double rip-stop improves tear strength and durability by 25%
- Aviation grade TPU lamination technology for ultimate durability
- High-volume valve allows for efficient and easy inflation and super-fast deflation
- One-way inflation valve with micro air pressure adjust button
- Quick deflation valve
- Weight: 16oz (20×72 regular)
- MSRP: $159.95

Everything is better when we work together
Fall is the perfect testing season in the Pacific Northwest. It’s wet and it’s cold, but so much of the best country is still accessible to hikers and climbers alike. Wet autumn days and frosty nights near alpine lakes were the backdrop for testing both the Lost Ranger and the Q-Core.
That’s an important thing to note, mind you. We have two things going on here: low temperatures and high moisture. That’s the quintessential combination to crank discomfort up a notch. However, Big Agnes promises comfort and the features of both of these products are designed to deliver. Let’s jump in with the pad first.
The Q-Core SLX is so named because it’s intended to be a ‘super light’ version of Big Agnes’ popular Q-Core pad series, but it retains many of the important features found throughout the line. It has a ‘quilted’ surface that’s comfortable to rest on and distributes weight evenly thanks to the internal I-beam construction. These pads also feature oversized outer baffles which help to create a bit of a cradle to keep you on the pad at night. That is one of my favorite features, personally, as it creates something of a tactile map that I subconsciously notice throughout the night to help stay on the pad.

It’s also lightly insulated, which is another important feature. This is usually measured with an R value, but Big Agnes doesn’t list one – instead, it suggests that the pad is good down to 15′. It accomplishes this through a mixture of physical synthetic insulation to create loft and an inner thermally reflective lining. I’d be reluctant to use this pad on snow at the recommended temperature, but I think it would work on a dry non-conductive surface. Otherwise, bring a closed-cell foam pad to supplement.
The pad inflates very easily with a nice, big valve. It has a micro-adjust and blow-off valve that lets it deflate rapidly. Plus, the inside of the bag is treated with an antimicrobial to fend off rot/stank. One thing I have to note, though, is that in my testing and experience as a guide, Big Agnes pads have a problem with developing leaks. Fortunately, their warranty department has been stellar to me and my friends. There’s also an included patch kit that I’ve employed several times (on other Big Agnes pads) effectively.

Now let’s go onto the bag, the Lost Ranger 15. It’s obvious from the first glance that the Lost Ranger and the Q-Core SLX work very well together. The Big Agnes system means that the bad has a fabric sleeve on its bottom side that’s elasticized to accommodate a variety of pads. Correspondingly, the bag is basically uninsulated along its bottom because, after all, your weight compresses that insulation anyway. Better to rely on a good pad to do the insulating. It works well.

Big Agnes really does make some of the most comfortable sleeping bags on the market. All of the key features are here in excellent execution. Perhaps my favorite is the generous draft collar that is U-shaped to create a great seal either over your collar bone or up around your face. There are the usual hood and collar elasticized adjustments, which could be better if they used differentiated cording for each one. There’s also a big puffy draft tube along the zip, and an overbuilt anti-snag track that does an excellent job at keeping the zipper sliding smoothly.
Overall, the bag is cut very generously. You’ll notice this especially in the footbox where there’s just tons of room, and it’s also easy to see in the garment-style hood that has a very distinctive squared profile. This bag is built for comfort, not to be ultralight. And, of course, the fill rating is 650-fill of DownTek hydrophobic down; dependable in wet weather, but not flashy. Other bags in this temperature range can shed anywhere between an ounce and a pound off the Lost Ranger’s weight, but often at hefty price increases.

Taken together, the system works very well. The Lost Ranger’s sleeve locks the bag tightly onto the pad and you would have to be a Houdini to get off the pad in the night. That’s a really nice thing if, for example, you’re camped on snow or the tent floor is wet. Besides the obvious benefit for those who move around a lot, these important aspects can keep a wet night from turning into a miserable one.
The Good
- Sleeping pad is comfortable, distributes weight evenly and has oversized outer baffles
- Pad inflates quickly and deflates rapidly
- Lost Ranger’s ‘comfort’ features are some of the best around
- Bag and pad work very well together
- Anti snag zipper track is particularly good
- Some will love the roomy cut of the Lost Ranger
The Bad
- Big Agnes pads don’t have a great reputation in my books
- Differentiated hood and collar draw cords would be nice
The Bottom Line: Lost Ranger 15 and Q-Core SLX
Big Agnes continues to make exceptionally comfy gear. While I have my doubts about the longevity of the Q-Core pad, overall I am so impressed with the features of both the bag and pad. They’re warm and work well together, helping you forget about your gear and get a good night’s sleep.
Buy Now: Lost Ranger 15 | Q-Core SLX