I've noticed that the 2008 version of this same sleeping bag is 6oz lighter than this model. Does anyone know what caused this weight difference? Different dimensions, more durable fabric, more fill??

Tech Specs:

Material:

[shell] 20D ripstop nylon; [lining] recycled polyester; [stuff sack] SilLite; [storage sack] cotton 

Insulation:

800-fill down 

Shape:

mummy 

Draft Collar:

yes 

Max User Height:

(regular) 6 ft, (long) 6 ft 6 in 

Shoulder Circumference:

60 in 

Hip Circumference:

47 in 

Foot Circumference:

[39 in] 

Stuff Sack:

yes 

Storage Sack:

yes 

Degree:

20 deg 

Weight:

(regular) 2 lb 3 oz, (long) 6 ft 6 in 

Recommended Use:

Alpine climbing, lightweight backpacking 

Manufacturer Warranty:

lifetime