For a change, it's the first storage system I've used in about 20 years that works as it is written on the brochure. In fact, it over delivers. We have had several bad experiences in many ways with storage systems and when you speak about Pure Storage from their datasheets or any other material, it feels like they are going overboard with what they say. But then, only when you deploy it completely would you realize that in fact, at least some of what they mention is underrated and the system is not marketing BS.
The support is awesome. In addition, we could never imagine upgrading a production storage system during business hours without missing a beat and without dropping any sweat. In fact, you don't need to do anything but log a call with support 2 days in advance and allow them to provide remote assistance. They just do it for you and no downtime or loss in performance. We tried it twice and it still feels unreal.
In addition, when we didn't get their promised data reduction at our DR site initially, by the time we discussed internally and called them to check what to do, they told us that they had already assessed the situation, made a report for it and submitted it internally for upgrading our disk capacity free of cost. No words. Just great. By the way, funnily enough, after they added capacity, we started getting far more data reduction than they promised. Not sure why it acted up initially.
Performance. Be it - IOPS, latency, redundancy when disks/controller/network cables fail (yes, we yanked everything to make it fail, and it was fun) it doesn't fail. Even the unreal looking data reduction, they nailed it.
They said it takes maybe 30 minutes to learn their system and no training is needed. We laughed at them. Not once, but many times. I don't think it took us any more than 30 minutes. This is about the easiest system we manage in our datacenter. Almost zero learning curve.