Very good and clear article. Thanks for sharing!

Censorship of transactions, isn't much of a harm as long as you have at least one honest block producer that can include it. In the event of all producers to collude, the only way out would be to use a POW block every round and require the first witness in the subsequent round to build on top of a POW round (unless the mining queue is empty, ofc).

BTW, if you read through the article again and keep in mind the current discussion about segwit/bu on bitcoin, you may realize how difficult a situation there are in:

• miners decide which protocol/fork to build blocks for
• every validating node operator having his own choice

This means, that in order to "upgrade" bitcoin to either one of those, you not only need to convince a majority of miners (which doesn't seem to happen) plus convince all the validating nodes to join aswell (otherwise they would end up in a stuck fork).

Worst case scenario here would look similar to the ETH/ETC drama.

With DPOS, this is not as much of a problem, still, validators and producers need to switch over to the new protocol at the same time, however, since shareholders have to vote/approve on a fork, we can actually coordinate a hard fork. This is one of the major advantages of DPOS over ANY other consensus scheme, namely that it comes with a stake-based governance mechanism! Thanks for inventing it @dantheman!