First impressions: It works. It’s nice. It is new in ArcGIS Pro 2.7, and only works in ArcGIS Pro 2.7. ArcMap 10.8.1 doesn’t see it. It has many advantages (compact, modern, high size and name limits) over other geodata formats such as shapefile and file geodatabase. It is very similar to the geopackage in that it uses the open-source SQLite database. It also looks like it’s Esri’s attempt to push users off ArcMap and onto Pro by recreating the personal geodatabase for the 2020s.
If you are a member of a GIS team where everybody uses only ArcGIS Pro 2.7 (and whose data partners also only use ArcGIS Pro 2.7), the mobile geodatabase looks like an attractive proposition. In my own work experience however (1, 2), no GIS data-sharing partner has ever requested or delivered anything but the much-maligned shapefile. YMMV, and this will likely change going forward, but as of today this is my reality.
So where does that leave me? What should I do with the mobile geodatabase today? I will dive deeper and try to discover all the advantages (and eventual drawbacks) of the mobile geodatabase. I may eventually move my data out of file geodatabases and into mobile geodatabases (which will require an update to all my maps’ sources). And I will begin to offer mobile geodatabases to data-share partners. I think I know what they’ll say.