Wow ! that's less than half...
I still hesitate to keep mine in my backpack (I'm in the process of reorganizing all my gear in my brand new Marauder...)

Pro :
- it's versatile : can be used as a poncho, a pack cover, a shelter, a pad to sit in it, a blanket to lie on in wet grass, etc..

Con :
- it is "heavy" ...
- I always have some difficulty to wrap it over my backpack (not easy to "throw" it over my head AND backpack at the same time....it usually stays on the top of the backpack !)

Maybe I should keep it for 1-day hikes during summer times and replace it with rain gear (pants + jacket = 430grams 15.16oz) and a silnylon tarp (HH original rain fly = 320grams 11.28oz) for longer hikes, in spring or fall.

Now, at 10oz ... I would keep it no matter what.