Do you hand the agency your CRM or make them push leads into yours

Working out the plumbing for a service business I'm setting up around seller leads, and the first real fork is where the lead lives. Two agencies I talked to want opposite things.

The first wants to run everything inside their own stack. Their landing pages, their call tracking numbers, their CRM, and I get a login and a weekly report. Their pitch is that they can see the whole path from keyword to answered call, so they can turn off what isn't working within days instead of weeks. That's a real argument. Attribution falls apart the second the data crosses a system boundary.

The second says push everything into my CRM by webhook, and they'll live with worse attribution on their side. Their pitch is that the lead history is mine, the numbers are mine, and if we part ways I still have every conversation. The cost is that they're partly blind. They see form fills and calls, not what happened after.

I can see myself regretting either one. Owning the data feels obviously right until you realize you've also taken on being the one who knows why the campaign is underperforming. Where does the room come down.