Nothing wrong with a USGI canteen and cup. For day hikes I carry one, sometimes two if the weather is hot. Only one canteen cup to boil up a spot of tea.

A quart or two of water, a couple peanut butter and jelly sandwiches and a couple granola bars for sustenance. A zip-lock sized necessary pouch for odds and ends - sunscreen, chapstick, tiny FAK, etcetera. It all fits into a USGI butt pack with a shoulder strap fitted to carry everything. Strap a jacket or poncho over the top and I'm good to go dawn to dusk. Add a simple bedroll and I'm good for 24 to 36 hours.

I have thought of substituting a semi-collapsible two-quart USGI model I'm familiar with but the difference in weight isn't much and the standard plastic canteens are working pretty well. Two smaller canteens actually helps with rationing. Three-quarters of a canteen out; the same back. If it works out according to plan, half a canteen in reserve.

Way back I even carried an OD green USGI wool blanket. The Florida bugs finally ate holes in the blanket and I switched to a poly-fleece number and a small lightweight tarp, sometimes a small ground cloth. All three together are roughly four pounds but much more flexible than the wool blanket.

Yes, I could save weight on equipment and carry more water with a bladder system. A titanium cup would save an ounce or two. But I'm comfortable and familiar with my present setup for this sort of light hike and that counts for a lot.

Some people seem to take great joy in buying, trying out new equipment, and generally tweaking and changing their system fairly often. I tend to find something that works and then stick with it. Those USGI canteens are better than twenty years old and may outlive me.

One thing I have tried a few hikes is substituting bottles of water for canteens. Three one-liter bottles are about as bulky as two quart canteens. They are nowhere near as tough as the USGI canteens but they take a considerable beating, unlikely to be damaged if they ride inside a pack, and if one leaks I'm still up on quantity. Cheap. But then again I own the plastic canteens and they are working pretty well.