Recommendations to others considering ArcGIS Field Maps:
Use the beta app on Android, we don't use apple products within this company so unfortunately can't comment.
If you are continually doing the same style of surveys then make sure your templates on AGOL are set up correctly. This will make your life vastly easier.
Train users of the app in the office before sending them out on site. Review collected by and hosted on G2.com.
What problems is ArcGIS Field Maps solving and how is that benefiting you?
Collecting visual tree assessment data, British standard 5837 surveys, ecological surveys which can then be hosted on ArcGIS online to be displayed to clients seamlessly. Currently also experimenting using SWEET for phase 1 ecology surveys, whilst strictly not Collector the principles are the same. Review collected by and hosted on G2.com.