The verdict
For an agency or service firm that lives on proposals and wants the client to read, sign and pay on one branded page, I'd pick Better Proposals. The page needs little design work, and the read tracking shows when to follow up.
If you send proposals, quotes and contracts regularly and want templates and a content library of case studies and fee tables, pick PandaDoc. It also has a free plan, an API and an official MCP server.
Run one real proposal through both before you decide. Better Proposals puts CRM integrations on Premium and sells Nudge as an add-on. PandaDoc grows in cost with the number of seats, so start with a small pilot team.