ProcessMaker may require some learning, but it's made up for by the fact that it's completely open source and free to use and download. It's hard to complain if it's entirely free (ProcessMaker Site)
BPM is also a special type of software that allows you to basically create your own applications. It goes beyond workflow automation software, and allows you to integrate with other systems like ERP, DMS, and CRM, manage permissions and supervisors, and design custom forms, as well as create web entry forms and create reports. So while it may take more time to get the hang of it, I think a true BPM system like ProcessMaker is well worth the effort given the additional advanced features it offers.