Thread was "have you guys invested in cryptocurrencies ? and if yes, in which ones ?" and you listed the above mentioned ones. Seems like you didn't understand the thread.
No, I haven't read any of the whitepapers, why would I? It wouldn't change the fact that they are shitcoins. I do not care, if their source code is 100x better than bitcoin's. Not bitcoin = shitcoin
And their use cases are very speculative, which will matter for the coins long-term. If they succeed, congrats, you'll be rich. If not, as is quite probable, they'll go near 0.