Actually, I was just being a wise guy. I got turned on to WM bags by a salesman in a local shop (big surprise!) I had been using a Marmot bag (Hydrogen or Helium, whichever is rated for colder weather), but it only had a half zip, so I was looking for a summer bag. I asked about a Marmot bag, but the clerk said, "You really need to look at the WM Mitylite. It has a full side zip, and no hood, and is a great summer bag. I use one myself." (Have you ever met a salesman who doesn't use whatever it is you're looking at? ) Anyhow, he was right, and it was love at first sight, followed about six months later with the WM Megalite. (The Marmot bag went to a friend who was just getting into backpacking.) I'm still using both bags, very happily; my wife, who does not even car camp more than once a year, made me get a second Mitylite for use when we're visiting the kids, or they're visiting us (and, somehow, we end up on the sleeper sofa.) WM temperature ratings seem about 5 - 10 degrees conservative.

However, personal biases aside, there are some good bags out there. I never had any issues with my Marmot Hydrogen/Helium, and their ratings seem pretty accurate. I've also used a couple of Marmot's synthetic bags, and they worked well, too. I would definitely recommend their products.

I've heard good things about the REI and Campmor house brands, but have never used either.

Good luck - again, stick to major brands, and you won't go too far wrong.