Interesting interview
https://ir.nutanix.com/company/events/event-details/2018/Bar…
Explains the value proposition of Nutanix well IMO. At the 17 min mark they discuss the transition in their revenue from subscription to SAAS model. They are going from life of device license to term based (subscription). In both they plan to recognize software upfront and support through the period. SAAS is incremental and only due to things like BEAM, FRAME.