Yeah, the DriDucks are definitely worth dropping the 6oz, Ive spent alot more money saving weight than $20.
I agree with not spending huge bucks to save a little weight. You already have a really light bag with Arroyo, and a pack that is just as light as mine.
Some things I see you could save for little money is
the rain jacket - driDucks - 6oz saved - $15
Socks - what do you hike with? If you use trail runners, get some crew wool ones, mine weigh 1.8oz for the pair - 2.2oz saved - $7
polar pure - I used to carry the exact same thing around, but it tastes bad and takes a long time to work, and only works with water above 50F. So now I carry a small micro dropper bottle full of bleach. 3-4 drops does the same effect as the polar pure, and is perfectly safe. Chances are your local tap water has more than that. The miscrodropper with bleach weighs .5oz - 3.5oz saved - $3
so for like $25 you are cutting off 11.7oz, which is quite a bit for really cheap. That weight would add up alot over the course of a 10 mile hike, and would drop your base weight well into the 12's
edit: I see you live in Port Angeles, I'm biking along the pacific coast this summer, and was looking to do a quick backpacking trip in the olympics, and reccomendations?