The new A/B Email Testing is great. But what for our company would be an even bigger need is the ability to do the same in workflows. Either create 2 different versions of a workflow (the same way as the email a/b test feature works) or have a action Item in the workflow which splits the currently enrolled people with a predetermed probability. (50/50, 80/20).
We want to have different sequences to see which performs better in terms of certain metrics.
One of your smaller competitors ActiveCampaign even has this: https://www.activecampaign.com/marketing-automation
(they call it split action)