VWO shows you what happened. It still leaves you to work out why.

They overlap less than the category names suggest. VWO is strongest when you already have a hypothesis and want a non-technical way to build and measure a variant, and its visual editor is a real advantage for marketing teams without developer time. Mimetic is strongest at the step before: establishing what is broken, in which environment, and whether your measurement can be trusted. Plenty of teams run both.

Because behaviour data tells you where users struggle but not why. A recording will show you a user abandoning the cart. It will not tell you the express checkout button fails to render in the Instagram in-app browser, which is the kind of thing a systematic sweep across environments finds and a sample of organic sessions usually misses.

Yes, with a holdout. Changes can be served to a variant arm with the arm assigned server-side, and lift measured against the holdout with a significance test. It is deliberately lighter than a dedicated experimentation suite. If you need a large concurrent test programme with sophisticated audience targeting, keep VWO for that and use Mimetic to feed it hypotheses worth testing.

That is common and it is a feature, not a shortcut. A checkout that fails on a specific browser, an event that fires twice, a tag blocked by the consent banner: these are defects with a correct answer. You fix them and confirm they are gone. Experimentation is for judgement calls, and spending traffic to A/B test a bug is a way to lose three weeks.