TanteStefana2, it is pretty well explained in many places that isn't true. Any coin that employs mixing wlll have essentially the same bloat (linear factor expansion of transaction count and/or size), except that the base transaction size in Monero is much smaller than in Bitcoin, so even after applying the relevant multiple, the size may still be smaller. DarkSend specifically suffers from the same bloat as Monero, or worse, in terms of using standardized output denomination sizes (some other coinjoin-based systems don't do this and have other problems).
Dash has fewer/smaller transactions (by smaller I mean making paying fewer payees) on its chain, and many, many fewer using DarkSend (the latter is probably the bigger factor). That is the only reason it's chain is smaller. There is no fundamental technological difference at work.
With Dash it's a choice, that choice has kept our blockchain smaller.
I don't see how a smaller blockchain is any benefit at all if it comes from less use rather than a technological advantage. That would make Truckcoin a great coin.
In the near future, most wallets won't be using full nodes.
Every coin has the potential for thin clients with some (generally reasonable, though somewhat less than full node) degree of security, including Bitcoin and Monero.
After reading this thread, I have no doubt that one should stay as far away from Monero as one can.
I doubt that you even read the whole thread you would have seen that virtually everything if not everything in the OP was refuted as nonsense.