My 155g runs entirely through an Apex. Love the capabilities of it. Full disclosure, I'm a Cloud Engineer so I don't have any issue with the programming aspect. Not terribly hard, but not always intuitive.
That said, I'm going to move towards running lights and wavemakers using their built-in software, and return/ heater/ dosing pumps/ ATO on the Apex (skimmer is TBD). The one downfall I don't love is having a single point of failure,