The strong version of the hypothesis is basically the old "if your language doesn't have separate words for blue and green then you're incapable of seeing a difference between blue and green", which is conclusively disproven by all the cultures which don't have separate words but nonetheless are able to distinguish the colors when producing, say, complex patterned textiles.
And logically speaking, strong SW makes developing words for concepts impossible since strong SW says that from your perspective there's no perceivable concept you'd need to develop a word for.
Versions weak enough to stand up to empirical evidence tend to be "if your language makes it more complex to express a concept, it'll be more complex for you to express the concept". If you word it up fancy, you can get things like "people who speak language X do this task faster", but that's unsurprising if their language is giving them help at it.
>"if your language doesn't have separate words for blue and green then you're incapable of seeing a difference between blue and green", which is conclusively disproven
Well yeah, of course. Your eye has blue color receptors that send signals to the brain well below the level of language. Animals don't have language and can distinguish colors, after all. That's just like saying because English doesn't have good words to describe different textures, we can't distinguish the difference.
But the explanation of SW I've always heard is nowhere near that strong. E.g. that because English doesn't have good words for different textures, that information isn't making it to the conscious mind. E.g. we are much more likely to forget texture, not notice it, or not use it to describe things, etc. I don't' see how that's a tautology.
I know I grew up without a really conscious separation between the different tastes. E.g. sweet, sour, salty, bitter, and umami. Obviously I could taste the difference. But I couldn't describe the type of food I felt hungry for, or explain why something tasted good. As an adult I've found distinguishing these categories consciously is very useful.
I think you are underselling the empirical evidence in favor of weak Sapir-Whorf. In the 70ies Rosch did some famous experiments in Papa New Guinea with speakers of a language with impoverished color vocabulary that demonstrated that colors outside the vocabulary remained salient (and were e.g. used to categorize objects).
However since then there has been a fair amount of research that shows effects which go beyond what you would seem to allow above (e.g. hemispherical effects on color discrimination, http://www1.icsi.berkeley.edu/~kay/tics2.pdf has some examples).
