Okay, I got some pictures to show bulk and weight. I put both pieces into a piece of organza (think: noseeum) and compressed them as much as I could.
What's that, the size of a baseball? Maybe a little bit bigger? At any rate, that's the most the tube itself can contribute to the "bulk" in your pack. Everything else is up to you. If you ask me, that's not a lot of bulk to contribute for a lot (A LOT) of convenience.
And, just for the sake of thoroughness and comparison, here's my top quilt, underquilt, and hammock stuff sacks all given the same treatment (cat not included):
So you can pretty safely subtract that volume from the volume of the slug tubes since they replace all those sacks.
Oh and.. because, y'know... you just have to 'round here...
184 grams = 6.49 ounces = 0.40 pounds.
Anywho, hope this helps some people get a better sense of the volume the tube adds to your pack.