It doesn't help that, if you're a non-expert, it can sometimes be VERY HARD to find reliable, consistent information about some of these products.
The LED Museum is a good exception to this rule, but there's no equivalent that I've found for sleeping bags, or tents, or other critical items. It's one of those things where there's word of mouth, but nothing comprehensive.
ETS is another exception-- product reviews are very good here for survival gear. Doug isn't afraid to name names and point out strengths and weaknesses.