Widen your field of view a little. That Red Chair NWPA was probably there to help you celebrate the completion of your AYOG Geigerrig rig.;-)
So from what I see here you got a Sawyer in line water filter at REI, a 3.0 liter hydration engine from Geigerrig and hooked it up to a 3.0 liter Platypus Hoser. It looks simple and efficient.
I'm guessing at about $130.00 in parts alone, is this correct? Have you weighed it yet? I'm really interested in the weight of the Geigerrig hydration engine. The Hoser and the filter probably weigh in at about 5 ounces.
I personally do not use hydration reservoirs but I have long been looking at the Sawyer unit for filtration. I really like being able to "pump up the volume" so that I could fill my bottles and cook pots quickly.
Just saw your last post after I hit the post message button on this post. 11 ounces total for the whole system minus the approximate 5 ounces for the Hoser and filter leaves 6 ounces for the hydration engine. For my application the total weight would probably top out at 7 or 8 ounces for the filter and hydration engine.