NEM has a long line of firsts.
- A new consensus mechanism called POI.
- First ever P2P time sync of nodes. (great for security of the chain)
- First use of the Eigentrust++ as a security clustering algorithm allowing node reputations to be given and shared to their neighbor nodes in clusters, making it very difficult for a node to give false information consistently to the network. (great for security of the network)
- First use of a new kind of transaction spam guard. It targets the specific accounts doing the spamming and raises their transaction fees, while letting the global transaction fee rate stay low. (good for the chain)
- First blockchain with a multisig 2.0 protocol. NEM’s version of multisig doesn’t make new accounts for a multisig address, instead it takes an existing account and makes a contract over it with other accounts. This form of multi-user accounts can make any form of M of N with ease and can also can have the M or the N edited with ease as it is simply just updating the meta data of the blockchain based contract. This form of multisig also has blockchain based notifications so transactions or updates of the M of N are pushed to the wallets as transactions to sign. (great security and ease of use for the user. simply the easiest and most flexible multisig in crypto)
- NEM’s multisig is so easy and flexible to use, it can be used as a foundational tool for DAO’s.
- Mosaics are the most advanced token creation feature in crypto allowing for many advanced 2.0 features. When creating personalized blockchain based tokens, the mosaic can be created as mutable, immutable, divisible, not divisible, levies, transferable, not transferable, descriptions, and a name as a part of namespaces. (great for businesses)
- Along with mosaics, NEM will also released its new naming service, Namespace, that is also be the most advanced and most integrated naming service of any blockchain. (great for reputation of businesses that build on NEM as all projects can be under an umbrella name or or even sub-domains)
And there is more.....
Messaging, which can be done unencrypted/encrypted/hex. (great for users and programmers)
A
light wallet that can easily be adapted by third party devs as it is pure pure JS/HTML/CSS. Any wallet may interact with any node on the network safely. (great for users. wow!)
Node Rewards supporting
Supernodes. (added network strength)
And........
EASY to use universal APIs for just about everything a person can do on NEM. This means it is a great platform for businesses to build their applications on.
15 second blocks in a truly decentralized network are not realistic, many will be orphaned. Did they test in a private network, intranet? One other problem of scalability is the size of the blockchain, has this problem been solved by NEM? Imagine you pump 2 million transaction per day for 30 days, 180 days, 365 days.
Yes, as stated in the OP it was conducted on a private fork. That said NEM is looking how to scale the right way. It is very important to us. In fact everything that is built on NEM is built considering "will this scale?", and the recent test is one proof of it. We look forward to in the future making more announcements about this and hope to add more "firsts" to the NEM list.