I have most of them- Aqua Trainers (7gal and 2.5gal), 5gal Scepter US military spec cans, Rotopax, MSR dromedary bags, Camelbaks. Over time I've come to realize I'm always struggling with room/weight when the whole family is along for a 3+ day trip so having the larger hard-sided water containers just doesn't work for me. I've gone down to this setup and has been working well so far:
1. 10L MSR dromedary bag (2.5gal) on the rear floorboard or anywhere I can find the room for it, very flexible, literally
2. 2gal RotoPax (along with a 3gal Rotopax fuel container)
3. 100oz Camelbak reservoir hanging behind my seat from the headrest, perfect for while driving
4. 100oz Camelbak Mule, perfect for the quick day hikes
5. 50oz Camelbak for the 10yo, perfect for the hikes
Plus a couple of Nalgenes in 32oz sizes for around the campsite use. Extra water is always good but give or take we have about 7 gals of water and usually more than what we end up using (2 adults, one child and one dog). I may get another 10L MSR bladder and sell off my other containers.