The REI Co-op Igneo 25 is a solid bag that offers comparable performance to other often much more expensive bags, such as the Western Mountaineering MegaLite, Marmot Phase 20, or the Western Mountaineering UltraLite, but at nearly half the cost. The Igneo is a slightly higher-end bag, at a more middle-of-the-road price. It offers decent quality 700-fill water-resistant duck down, along with respectable shell fabrics.
All that said, we still prefer the Western Mountaineering UltraLite or Marmot Phase, as they offer higher-quality down and a lighter weight shell fabric. This creates a warmer, lighter and more compressible bag; while the weight and packed volume the differences aren't huge, the price differences are giant and both of these bags are more than twice the price and only slightly warmer, lighter, and more packable.