The key feature of NEM is Proof-of-Importance and how this algorithm incentivizes desired behaviors on the network. Here's how I think about incentives for each of the common blockchain algorithms:
Proof-of-Work : Those with the most computing power to solve complex math problems win the right to harvest blocks and earn the corresponding reward.
Proof-of-Stake : Those with the most accumulated currency have the highest odds of getting to harvest a block. This can incentivize hoarding and gives an instant advantage to someone with a lot of capital coming into the system. Steem addresses the latter issue to some degree through the use of witnesses who are elected by users (votes weighted by how much Steem Power you have).
Proof-of-Importance : The right to harvest is awarded based on a combination of your stake (amount of currency) and how many transactions you have participated in. This reduces the incentive to hoard and allows those with fewer resources to more easily get a chance to harvest.
P.S. This is my first Steem post, really enjoying the platform so far!
Thank you for your detailed explanation, you made it so clearly
Glad I could help!