Having just moved a client from GA4 to Mixpanel, I can tell you the answer is neither. Both are a headache, but in different ways.
Google's import is clunky and forces you into their BigQuery ecosystem—more infrastructure than most teams need. Mixpanel's process is simpler on paper, but their CSV templates are rigid and their data model is a walled garden. You'll spend more time massaging your event names and properties than actually migrating. The transition took three weeks, mostly due to data cleanup. GA4's sampled data is a nightmare to reconcile.
CRM is a means, not an end.
I'm Ethan, a community manager at a mid-market B2B SaaS firm. I've helped migrate our product analytics twice, first from Classic GA to GA4, and then from GA4 to Mixpanel, so I've felt the pain firsthand.
Here's a breakdown based on our experience migrating about 90 million monthly events.
**Initial Setup & Complexity:** GA4's import process is essentially a BigQuery pipeline. You're building data transfer jobs and writing SQL transforms, which is a multi-day engineering project. Mixpanel's UI import is simpler, but its strict schema requirements meant we spent a week manually remapping over 300 custom event parameters to fit their taxonomy.
**Data Fidelity & Cost:** A hidden cost with GA4 is sampling on exports once you hit certain volumes, which makes pre-migration reconciliation fuzzy. Mixpanel doesn't sample, but their pricing model (based on monthly tracked users) created a surprise 40% cost increase post-migration as we onboarded more users.
**Ongoing Maintenance:** GA4's linkage feels permanent once set up. Mixpanel's simpler UI import is also a recurring need; every new event type requires you to go back and ensure it fits their template, adding incremental ops work.
**Vendor Support & Documentation:** When we hit a BigQuery quota wall, Google support was slow (3-5 business day response). Mixpanel's support answered in under a day for schema issues, but their docs often assumed perfect data, leading to several failed import attempts.
I'd pick Mixpanel if your team is non-technical and your data schema is simple and stable. I'd pick GA4 if you're already on Google Cloud and have dedicated data engineering resources. To make a clean call, tell us your team's technical capacity (analyst-only vs. dedicated engineer) and your tolerance for variable, event-based pricing.
Keep it civil, keep it real