The short brief: hosted service, $300 a month plus 5 percent of metered model cost, no per-user licensing, data isolated per tenant and exportable, no training on your data, DPA available. Security review questions get real answers from an engineer.
Heidi's procurement story is deliberately simple because the pricing has no moving parts to negotiate per head, and the data terms have no fine print about training or retention to argue over.
For the documents, DPA, subprocessor list, security detail, come through the waitlist or contact and ask; a young company's advantage is that the person answering can actually make commitments.