Ray, I have the +20F Long Slick Bag in their compression sack and it has been my constant companion in my S.O. Tech Go Bag Extended
where it fits perfectly. I never would have been able to fit any of the issue sleeping bags in there and had half the temp protection. It's a little slim in the leg box and shoulders (I'm 6'4'') but that helps keep in the heat and it hasn't had a problem going well below +20 (+2 last use). I have used it multiple times and the only detractors that I've run across is the crinkle sound (which has mostly gone away after several uses) and the velcro tab that secures the "flaps" doesn't have anywhere to go if you leave the zipper open and it tends to scratch. These are both very minor and I would tell you to get one since they are light, small-ish when compressed (more so than any issue gear) and retain heat great for those cold desert nights.I love the EMR but it's honestly too big for my applications out here; it can hold my XL 56-P helmet, sleeping bag, extra clothing, etc etc etc but with a gunbearer over armor it's just too much. Without armor I'd reconsider since it can take the job of three bags but that's not an option for either of us, I'm sure. I looked at the Marauder, Zulu and ZXR and liked them all and honestly think they would fit my needs better but hindsight is always 20/20. The S.O. Tech Extended is actually an excellent
bag for a quick go-bag and I would highly recommend it; the vertical styling with handles on both ends plus the messenger-style shoulder strap lets it slip in small places (vertically or horizontally), the two large pockets on the front hold at least 4 .223 magazines each while the interior holds a toiletry kit, sleeping bag, extra set of clothes, flipflops (in the hydration pocket) multiple CLIF bars in the stuff pockets and the MOLLE on the sides let you put whatever you need to hold the gear you get to most often.