I think you are missing the point of the exercise, Vince. This is a lot more than a PSK.

Realistically, when you look in your tin, how complete is it? Do you have a cup that you can count on? Or a water container that can take being sat on accidentally? Do you have more than a few days of water tabs? Do you have a flashlight, or a real knife, to replace the ones that just fell out of your pockets into at least 20 feet of water at night? If it is like mine, you don't, not unless it is cased in a mess tin or something similiar, in which case it is as bulky as the Nalgene kit.

A water bottle with a mouth big enough to let gear pass is inheriantly waterproof, so your gear stays dry- toss in a small clay desiccant packet and it will absorb whatever moisture is in there. It's also in one place, and it's really hard to squash the stuff in it- I've seen Nalgenes that looked scuzzed enough to support the claim the were driven over. And it is big enough that if you have to find it in the dark, in the rain, in 30 seconds or less, so yes, a Nalgene based kit is bulkier than the PSK. But it isn't a PSK, but a larger size of survival kit.

As someone who uses tinned kits as well, I can't say that they will take the same degree of abuse, nor will they float, nor would I trust tin and electricians tape to keep the water out for more than 20 minutes. And in fact and truth, any truely pocket sized kit in anything other than a Pelican mini-case or an Otter-box that claims to be was well protected against the elements as one in a Nalgene. That doesn't mean that I will be retiring my tinned PSK, but for my parents or my sister-in-law, I'm sorely tempted to build just the kit I describe for each of them.

Never compare a pocket knife to a hunting knife, nor a hunting knife to a sword or axe. It is never fair to anyone. For the average person, what's better? A bigger, more capable kit that they can find in their car and can forget about for a few years, or a pocket kit that has been skeletonized to the bare bones and is lost in the trunk?