At 61 years I tend to stiffen up quite easily especially after a long day's walking so I opted for a M 300 with a short zip, easier to get into you see. In warmer weather, the bag closed is far too hot for even a cool summer night and I tend to open the zip, turn the bag over, stick my lower half in the lower half of the bag and drape the unzipped top half over me like a quilt. I get a very comfortable night's sleep that way. Alternatively, I use my Tesco down bag in high summer or even my Vango Ultralite 100 when it's really warm. Within the broad constraints of season and ambient temperature I sort of chop and change on a whim.
In my late teens and twenties I carried a Lofoten down bag which had no zip and at around 2 Kilos was considered the lightest of lightweight bags. I had no problem getting into it then but that was over 40 years ago when I was young, supple and agile. I had that bag until the cotton, yes cotton, inner just wore too thin and rotted away. It was imported from Norway, cost me a fortune, about £35 I think, and lasted a good many years even though it had loads of hard use in my halcyon days
Edited: 11/03/2009 at 12:08