Here is my system:
3 Liter Platy: 1 1/2 oz.
Sawyer Squeeze Bag: 1 1/4 oz.
Filter: 3 1/2 oz.
Tornado Tube: 1/2 oz.
Two Caps (one for Platy, one for Sawyer Bag): 1/4 oz.
Bag: Which holds the entire thing and grabs water from ponds and lakes: 1/2 oz.
Entire weight: 7 ounces (more or less).
Not the lightest hydration system in the world, but very flexible. Most of the time, I don't carry water. Nor do I wait for water. I have everything but the platy on the outside of my pack, so I can just sip and go. I do this numerous times during the day. Keep in mind, if you are carrying water, it is probably heavier than my system (who carries less than one cup of water?).
Around camp, I connect the Tornado Tube and I have plenty of clean water for sipping. When I hike to the top of a mountain, I fill with clean water, or dirty water, or both. I have the ability to hold about 7 liters of water.
Unless you have the patience to wait for tablets, I don't think you can get much lighter than that. Just like tablets, it depends on where you are going. Tablets make sense if you are in a dry climate and have to carry lots of water. Or they make sense if you are really patient and like to "camel up". On the other end of the spectrum, if you are always drinking from the Sawyer filter when hiking, then it makes sense to leave the Platy and Tornado Tube at home. Just drink and go when hiking, and drip into your cook pot when camping. So, that will save you a couple ounces (since the Tornado Tube is useless without a Platy). But the trade-off is drinking from a clean water container that you can stuff into your pack.