Ask HN: What is the “best” SaaS ERP system? What's important?

Adopting an Enterprise Resource Planning tool is an aspect of my job that I dread. Here is a list of things I think are important for the decision:

-Totally based in the cloud (we manage 0 hardware) -Offers good web applications for non-technical users -Well-documented feature-rich API for engineers (Twilio’s API docs are the gold standard here) -~Instant/phone technical support to troubleshoot API and general Qs -Good documentation overall -Ease of data in and ease of data out (no lock-in) -No Contracts -Affordable

What are your experiences with ERPs, HN?