Do you mean HEC- GeoRAS which was the old method to map floodplains? Or do you mean the alternative software GeoHECRAS. If you mean the first one, the process is different as it is mapping 1D results, if you mean the later, I recommend from an agency review standpoint, that you continue to use Corps products
I’m talking about the CivilGEO GeoHECRAS software. It’s not a replacement for Corps software; it’s just a wrapper with additional functionality. The deliverable files are the same.
I have had many meetings with the Civil Geo guys so I know what it is and never saw any benefits, I also had multiple colleagues tell me how continually buggy it was and typically only worked with example projects. If you have extensive years of experience in RAS, I suggest to do without it as sometimes HEC-RAS can have its own ridiculous bugs. I find no use in their product other than their auto mesh generating based on the underlying terrain, but as I mentioned, it was too buggy to be beneficial.