this Alps Mountaineering Slick Rock 20 degree bag shows an 8x17 stuff size,but since it is Primaloft shouldn't it have a much smaller compression sack size? anyone have any experience with this bag or the company who makes it?

Tech Specs:

Material:

300T round ripstop nylon 

Insulation:

PrimaLoft 

Shape:

Mummy 

Draft Collar:

Yes 

Max User Height:

[Regular] 6ft (183cm); [Long] 6ft 6in (198cm) 

Shoulder Circumference:

[Regular] 58in (147cm); [Long] 60in (152cm) 

Stuff Size:

8 x 17in (20 x 43cm) 

Stuff or Storage Sack:

Stuff sack 

Degree:

20F (-6.7C) 

Weight:

[Regular] 2lb 15oz (1332g); [Long] 3lb 2oz (1417g) 

Recommended Use:

Spring, summer, & fall backpacking, camping 

Country of Origin:

China