I have two different PSK for different applications. First, I have a PSK on steroids in a Paraclete GP Medium Pouch that I carry whenever I am in the field. It is carried either on my belt or the waist belt of my backpack. It works very well, and keeps all my survival stuff in one place so if for some reason I have to dump my pack I can grab this pouch and go. The contents of this pouch are merely for survival, and items I'd need under normal conditions (compass, matches, knife, etc) are duplicated. This pouch is great as long as you don't have breakables in the kit (which I avoid in my PSK), light durable and realitivly inexpensive.

My second kit is smaller and simpler, carried in an 4.5"x 7" Aloksak with two smaller 2"x3"(?) organizing smaller items. THis apck can be carried in a BDU pocket or in a small camelback easilly and usually resides in my Bug-Out bag on the front seat of my truck. It is the kit I carry when trail running or mountain biking and my EDC kit. Thes bags are superlight, more durable than ziplocs but are somewhat easy to tear, yet they are pretty much dirt cheap!

I choose not to use hard boxes for my smaller kits due to weight and bulk, however I do like pelican and otter boxes for sensitive and expensive gear, most of this stuff isn't survival gear but electornics I need to take to the field for other reasons. The cost in weight, bulk and money is worth it to protect expensive electronics and optics.