Generally its know that the plants in deathcubes originated from the coastal locations. Mountain location only just recently became available through a few CP vendors, and even then they arent sold very often.
The stuff i received at the place i worked at, i was good friends with the supplier for awhile before we lost contact. He said his plants originated from divisions and TC he performed after a friend of his collected seed some 10 or 15 years back from a rather colorful, strong growing group of coastal cobras.
you might get lucky and get a stronger clone of the coastal location clones, but if you dont, youd better figure out a way to baby the hell out of it because its more than likely gonna fuss over something.
The mountain location type has adapted more to extreme variations in temperatures, humidity, etc. and is more tolerant because of that, people use variety to seperate the two because its more simple, sure there generally isnt any morphological difference between the two, but those of us with experiance between the two varieties will generally swear by the mountain location plants.
I'll throw in my 2¢;
Phenotypic Plasticity. My personal experience has been that, for one, properly potted Darlingtonia labeled as "coastal" perform quite well in even in sweltering conditions. Further, "coastal" stands of Darlingtonia regularly see the full brunt of Oregon midsummer heat waves, and the plants in situ handle them just fine. I feel there's an undeniable possibility that
heat tolerance and vigor is not directly correlated to location at all.
I've grown these plants from seed for five years now and have seen huge variability in durability and preferences among my plants, and I'm sure that if I'd grown them indoors, the seedlings that succeeded and survived would have totally different mean characteristics than the crop I have on my porch. It's
often the case that a species' genetic variability produces offspring with a spread of different growth rates and preferences, simply as a matter of insurance against unpredictable events like droughts, landslides, flooding, climate changes, etc.
I'd be willing to bet money that two batches of seed from differing locations would yield roughly the same number of desirable adult clones if well cared for in identical artificial conditions (as in potted, but still with natural sun and exposure to weather.) I would expect the mountain plants to produce slightly more due to the conditions those groups see, but they would be on the same order of magnitude (relative to seed/seedlings started) as the coastal strains - I wouldn't be surprised if coastal came out on top, either. The probabilities related to the genetics of the matter are too delicate for reliable intuitive reasoning.
I don't think this question can be properly argued without at least one survey of plants with location data and possibly genetic testing as well. Can any of us say that our cultural practices are really scientifically objective? Darlingtonia cultivation still isn't very well understood; I think it's more important to focus on things like conservation and study. I, for one, find it very informative to see the number of success stories like in the original post - even abused death cube plants can often be rehabilitated.
~Joe