Blackcoin has a few very strong advantages going forwards against Bitcoin, Litecoin, and all the other Proof of Work coins. It's the developmental leader of Proof of Stake, which cuts out the middlemen of Proof of Work, the miners, allowing holders of the coins to do the work and receive the benefits of mining instead.
As can be seen in the bitcoin community at the moment, users and miners when separate can quite easily be at odds.
Another benefit of Proof of Stake is that it eliminates the competition for ever increasing processing power.
Essentially, in Proof of Work, the lottery of who records each block goes randomly to someone who's mining. It's a common misconception that PoW mining is meaningful work, it's random numbercrunching, it's purpose is to determine a random person to write each block in order to decentralize the network. Ironically the ever increasing competition in order to solve blocks has actually ultimately lead to the formation of pools, and the centralization of the network.
In Proof of Stake the number of tickets you have in the lottery of solving the next block is determined by how many coins you have staking. The probability of solving the next block is essentially however many coins you have staking over however many coins on the entire network are staking. As long as you stake you're actually beating inflation, which is a nice side effect of this method.
Proof of Stake is not only a more elegant solution than Proof of Work, but yields more benefits to those who use and hold the coins. Proof of Stake is also more scaleable, as blocktime is unrelated to security, and can simply be shortened to meet scaleabilty needs, something that Proof of Work cannot do.