I have for sale a Montbell SS Down Hugger #5, rated to 40 F. I can verify this, as I've spent a total of around 10 nights in this bag, some of those night being down to 40 F.
Always stored in its large cotton storage sack. No tears, no smells, no stains. The bag looks like new. Pictures upon request.
Edit: Oh yeah....always slept in a bag liner in this.