Considering purchasing, what is your opinion?

Before working at Nintex, I was a customer for 4 years. And what you described are exactly the type of things we used it for. In addition to the things, you mentioned we also used it for Lease Vehicle requests, Internal Innovation submissions, Board Paper submission review and approval process and Project review and approvals etc. The IT Project group owned Automation and document management and as we typically sat outside of the main IT group, we had a lot more exposure to the business and got used to automate all sorts of crazy requests, using SharePoint as our backbone. It allowed IT to remove MS-Access from people's machines though which stopped the spread of non-compliant "Mission Critical" apps popping up that were never backup up and were very hard to manage.