It's tiered, they have local nvme that gets written back to object storage.
npm install hasn't bothered me, but I know of people with massive npm issues that would like faster first installs. Fortunately, it's incrementally quicker after that.
The storage performs pretty well for running claude + my dev. It'll improve immensely in the next few months, though. We should be able to get near native NVMe speeds for the working storage set on reads/writes/flush/fua.