The UI is very easy for anyone who has never used it before - this makes onboarding new users quick as well! I have not yet seen any downsides with using it internally or externally within our organization.
It's hard sometimes when you're working remotely (or in another time zone), but there are ways around those issues if they arise. Try out both versions so you know which one works best for your needs/situation. We've been able use reliagreymatter more efficiently than we could manually pulling info into various spreadsheets.