The reason you would use this over RAM is persistence, it doesn't need to stay powered to keep the data.

If all you need is a massive amount of temporary storage for some algorithm, you'll still need RAM, but if you want a stupidly fast backing store for a huge amount of source and then output data, this is pretty incredible.

When your computation fits in RAM, what's the point of a lower latency backing store that does fewer gbps per dollar?

Many of these systems have write caching enabled, which means that on critical power failure, some data will be corrupted. And often such system have back up supplies.

Let's be clear here. The real reason people used this stuff was that it was 3x/4x cheaper than RAM.

Have you considered write-back cache scenarios? Can't use RAM there. Stuff like this would be fantastic for those applications.

That sounds interesting, can you tell us more a about the system?