Good post!
It's also worth pointing out that from a given manufacturer the tensile strength (rated strength of the chain before it breaks) for their chains will often be the same for non ring, O and X ring types, within the same size and material specs. We pay the extra for having the sealing rings as they should last longer and reduce labour and sprocket costs for their replacements.
I remember happy days when you had two chains for your bike plus spring links and these were rotated every couple of weeks and re-lubed with Linklyfe, a boiling hot tin of grease on my mum's cooker which you put the chain in to get the grease back inside the rollers. Then hung up to let the excess drip off. Once almost set my shed on fire when it did this on a camping stove, similar to a chip pan fire. My brother still does this on his classic Triumphs...