AFAik, with NX-9000, Nutanix brings Webscale to Flash.

Before you begin, I strongly recommend you read these fantastic blogs.

goodbye-dual-controller-arrays-hyperconvergence-meets-all-flash/ - @LukasLundell - explains why flash needs webscale architecture.
nutanix-unveils-industrys-first-all-flash-hyper-converged-platform - @Nutanix corporate blog.

All Flash Arrays from the Storage Vendors still have same underlying problems of three tier architecture.

Here is the main bottleneck caused by dual or single storage controllers in the array. 

• insufficient processing power so it is unable to keep up with the performance of SSDs 

IMO, flash exposes the flaws of the three tier SAN architecture. All the goodness of flash is attenuated by three tier SAN architecture.

It is similar to a fast car (flash drives) being pulled by two horses( storage controllers).

three tier architecture

In a similar way, flash will highlight the benefits of Nutanix Architecture. All the goodness of the flash is amplified by the Nutanix Architecture.

•  distributed storage controllers removing CPU bottleneck
•  reducing network traffic by localized reads. No need of expensive SAN switch.
•  Distributed elastic and resource efficient deduplication - store more for less
• Flexible grow as you go! Future proof your Flash investment! Need more Flash capacity and compute power - just add a node - less initial investment.
• Flash can take advantage of convergence: hitless upgrade, share nothing architecture, elasticity - add node /remove node, no Single point of Failure, fault domain awareness, tunable resiliency with RAIN - network mirroring) - webscale your flash
• DR /Metro cluster - protect your VMs. Note: Remote Nutanix cluster can be less expensive hybrid (SSD/HDD) nutanix cluster. - protect your data in the flash for less cost.
• Nutanix innovates new features at a faster rate than other storage vendors due to distributed architecture and not being in kernel space. Unlike other storage vendors these upgrades are non-disruptive and easier via OneClickUpgrades - feature rich flash
• At the same time, be hypervisor-agnostic same as legacy AFA. - hypervisor agnostic 

Flash and Nutanix are made for each other and this convergence will bring out the best, benefiting the customer.

It is better to have horse power converged within the car rather than having two horses pulling it.( that is just my opinion)

Finally the specs of NX-9000