We have a PoS algorithm coming out within the next day or two that we will extend to a DPoS scheme that is provably secure. DPoS still suffers from lack of incentives modeling for both participation of the voters and the delegates themselves. The next generation will need to more formally address these concerns.

With respect to its quality as an algorithm, the idea has been around for awhile under the term dynamic quorum paxos. The novelty has been using a PoS scheme to select the quorum. Lisk does use DPoS and would be the first candidate for potential improvements moving forward.