Lucky, I'm not knocking your bag here, so please don't think I'm trying to be argumentative. It's up to you. If that bag meets your needs, great. You scored for $20.
But I tend to walk into some pretty extreme places (e.g., high altitude - > 10,000' in NM in December) and have been slammed by some pretty nasty storms. (One I remember very well was in the Sangre de Cristo's east of Santa Fe at Thanksgiving. The blizzard lasted 2 days. Winds were clocked in Santa Fe at over 70 mph. Up where I was, just below the tree line, it honestly sounded like a 747 coming in.)
My latest project is to consider a move to Alaska around Fairbanks (I've decided that the wilderness in the lower 48 is a bit tiny for my taste.)
In places like that, my life depends on my shelter and insulation. A plastic tarp under a bush in a $20 bag may be fine for you. That's great. I personally want something a bit more.
And STMTNMAN, I completely agree that mountain men in days of old did without high tech gear. I also understand that they had horses to carry their heavier wool blankets and animal hides (I don't) and that more than a few of them froze to death or lost limbs due to frostbite. (Jim Bridger was a direct relative of mine, so I've done a fair amount of reading on the topic.)
I do hear what you're saying about tarp tents, too. I like tarp tents. I use them on occasion when I know I'm going to be in a fairly protected area and not exposed to raging mountain storms. But otherwise, I'll take a regular tent.
If you're into minimal (like I am), you might also consider something like a
Black Diamond Betamid. Less than $100; nearly bombproof. Carry insect repellent.
With all that said, here's a few more thoughts just for consideration. No "truth" implied (since all this is relative and opinion driven). YMMV.
it appears to be 5 times heavier than equivalent new models, that could be why it was on sale!
Yep, that could do it. The bags that some of us are talking about (e.g., Marmots) are backpacking/mountaineering bags. 11 lbs is just out of the question. Mountaineers often count ounces in an attempt to shave weight. Down weighs less than synthetic fiber, and compresses better.
If you're not going to be on foot much, or just like heavy loads, 11 lbs will do fine...weight wise, but ...
some sites say -10 and other -20 or 30 degree rating
Hmm. Why am I skeptical of -20?
I saw a program recently on army equipment produced for WWII soldiers going to Alaska. People living in Georgia designed it, having no clue what the extremes of weather in AK were like.
The troops went up and were miserable: cold and wet all the time.
Don't know when your bag was produced, but if it's that old (unlikely), then I'd take those estimated ratings with a bag of salt.
In fact, I tend to take most statistics on bag ratings with a huge grain of salt. (See my caveats in an earlier post above on bag ratings.)
Then, again, just to reiterate: if it ain't broke, don't fix it.
Nem