I've recently performed an extensive, not quite exhaustive, analysis of all the eSignature platforms. While I haven't used them in a day-to-day setting, I have a solid sense of how they stack up.
As always, which system will work best for you depends on the complexity of the workflows you are trying to automate, and how much integration you need to other systems. There are so many options out there, and almost all of them are cheaper than DocuSign in most circumstances. But it depends on factors like:
Adobe sign is a super slick system, with deep integration with Microsoft 365 (including Teams), and is more affordable than DocuSign. It seems to match it pound for pound, with better pricing. It also comes with a workflow tool that DocuSign can't match unless you get into their contract management tool, which makes DocuSign even more expense. But, the workflow tool for Adobe requires a license for each user, and that gets expensive.
If you need to create a bunch of workflows for intra-office, self-initiated signing and or approvals processes, then one of the most impressive systems out there is airSlate (which comes with their signNow tool). You can even put self-initiated links on a public website for constituents to initiate form-signing processes. In that way, you can have thousands of esign or general "approval-required" processes without paying per Send. They are building out connectors to many systems and databases (already have MySQL, and MS SQL should be released this year), so it can almost serve as a light ETL tool. AirSlate requires 10 user minimum, which comes out to $5400 a year for nonprofits, but it would allow you to self-initiate thousands of approval processes that would cost 3 times as much is DocuSign.
For more affordable systems if you don't need the most advanced features, look at HelloSign (25% nonprofit discount). PandaDoc is very good system, but gets pricey if you need many user accounts.
Each system has its strengths and weaknesses. Hopefully that helps provide some differentiators for you to consider.
dan shenk-evans, senior consultant build consulting | transforming nonprofits
office (202) 808-3076 x 707