The verdict
For a small B2B team that nurtures leads, scores engagement and hands warm ones to sales, I'd pick ActiveCampaign. The automation depth is the stronger side, and it has a documented API, webhooks and an official remote MCP server.
If you run a small service business, such as coaching, consulting or an agency, and want to book, quote, invoice and take payment in the same place, I'd pick Keap.
If your CRM needs are complex, with several custom objects and cross-object reporting, neither is the final answer. Look at HubSpot or Pipedrive for the CRM. Both tools price by contact count, and Keap carries an early termination fee on annual contracts, so trial before you commit.