I haven't looked into Xtrabytes in details at this point but it's just a gimmick. That article starts off saying P2P is not the best and they're going to have a Chord network. Guess what. Chord is just one of several protocols for P2P networks. So it's just a gimick to make people that don't know better think it's some how revolutionary.
https://en.wikipedia.org/wiki/Chord_(peer-to-peer)
Couple other things from that article.
If they have in fact come up with something that solves many of the POW and POS issues with their POSign, then yes, that could be a very big thing. But until you get many of the real cryptographers to review it and give their analysis of it, there's no way to know.
That article says Masternodes are involved. When I hear that, I immediately know it's not trustless and has the risk of those being shut down someday. If the network needs those nodes in order to do anything, then it's point of failure and a risk. Given what I watched happen with spammers and hosting in the earlier days of the internet, its just a matter of time before all coins using some sort of masternodes starts getting shut down and pushed into a few of countries that you would never trust. Frankly, if POSign is great, I don't have a clue why anyone would throw in masternodes unless their only interested in the cash they generate. No one that is serious about crypto curency views masternodes in a favorable light.
Again though, I don't know all the details of the coin but from what i do know, I would rate it as just a coin to perhaps "day trade" but not long term invest.