The Redwood is a "heavy duty" oversized rectangle bag. The Redwood series use Techloft Insulation. Techloft Insulation consists of multi-hole staple-length micro-denier fibers that have a siliconized finish for maximum insulation, loft, and compactness.
I bought this because of the February snowstorm in Texas, and wanted to be prepared in case I lost power at the house. Being rather tall, a properly-sized sleeping bag can be a bit of a challenge. This actually goes over my head and will definitely keep me toasty in the case of a frigid emergency. I also have to note the straps. They're not that cheap, crummy elastic that some other brands use. These are good quality and, assuming you don't pull ridiculously hard on the straps, they should last the life of the bag.
I've been using the army mummy bags for years and wanted something more comfortable. This bag is big,comfortable and very warm. The quality is top notch. I've used mine a half a dozen times and love crawling into it. Like I said "No Regrets.