I'm testing it on a client LP to send data to facebook (custom audience for retargeting), adwords (conversion to create a custom audience for retargeting) and analytics. It works and it saved some time.
I'm not pro enough to say that doing this with GTM would be equal easier. I suppose it wouldn't. Besides that, I'm just scratching the surface and using it to track views but I already see that we can use it with forms and a lot of other custom events.
Negative points: The user interface is somewhat confusing and they should create better documentation or a few webinars (I already suggested those).
Support is cool. First answer in a few minutes and they were very helpful. And this is wonderful.
60 days refund policy so we are safe to test. I stacked 5 codes to use with my clients. Hope you don't get "jooicered", "verstered", or "fielbooked" :D
Overall, It is a good saas to play with, especially for small agencies or "one-man-shows".