Reviewers consistently praise Refrens for making quotations and invoicing fast, simple, and easy to learn, with helpful payment tracking, direct sharing, clean templates, and smooth quote-to-invoice workflows. Many say it reduces manual work and keeps client, billing, and sometimes inventory or CRM tasks in one place, with several also highlighting responsive support. The main complaints are limited customization, gaps in reporting and advanced accounting, fewer integrations, some workflow limitations like purchase order conversion, and frustration with invoice limits on the free plan.