I'm sure I'll take some grief from this because of the weight, but you might want to consider the AquaStar UV filter. I hike mostly in Pennsylvania with lots of clear streams along the trails. I carry a couple of coffee filters to use as a prefilter if I ever come across cloudy or murky water but have never had to use them.
Other than the big three, the Aquastar is the heaviest item in my pack at 8.3 ounces (plus another 1.2 ounces for an extra set of batteries). That does include the mesh prefilter that's good for straining out small debris that may be in the water and the lexan bottle that holds it. I've thought about sticking it in a Nalgene canteen (and even bought one for the purpose) but I like the protection of having it inside a hard shell.
Why do I still carry it? I usually hike with 2-4 of my friends and this is our water purifier. It kills bacteria and viruses and doesn't affect the taste of the water. It takes about 90 seconds to filter a liter of water which is then ready for immediate consumption. For us that's a real treat when hiking during the summer because you're drinking the water when it's at its coldest and most refreshing - not waiting for 30 minutes while it warms up.
It's easy to use - just fill the bottle, screw on the light assembly (which is attached to the lid), push the button, and then shake for about 80 seconds. From your avatar it looks like you hike with your children. I think you might like the idea of knowing that any boogies in the water are dead before the kids drink it.
It's just another option to think about. From the looks of the Meridian Design website, it's currently on sale for $69.