Personally and professionally, I've never received a OD document - ever. Until about 5 years ago we were still receiving WordPerfect suite documents with some regularity - after the Novell antitrust lawsuit was dismissed, WP files pretty much stopped showing up, but I know more people using the Corel WP X6 suite than you'd think but that's Windoze-only and this is a Mac thread...
There's only bit here that's rarely discussed about both MS's and OD file "formats" - they're just container files, just like a ZIP archive is a container file. The container file contains instructions/files to the relevant application and an XML file that contains the formatting and data - that's it. "Saving as" or "exporting" one file format to another file format is simply a translation/conversion of instructions in one application to make it compatible another application.
I use MS Office, and have on the Mac since the Office 6 Suite back in the 90s, and the Windows Office suite since Office 2000 - they're just applications to me and I don't care which OS I'm using with them. My take is use the tool that's convenient for your needs, and the needs of the persons you interact with while keeping in mind that some elements - macros, application-specific features (macros/formatting such as tracking and form fields/file paths) might not get "translated" - application-specific features can get cropped out when exported mainly because they don't exist in the target file format.
Using Keynote as an example - all of the template/text/layout items might get exported to PowerPoint (as an example) but the nifty animations and alpha channels could get dropped/flattened and vector-based images could get rasterized...
What I do, and have for over 25 years, is pick up the phone and ask the client/recipient what application they're using. The people I interact with, when they make that call to me - I tell them to use Office, the latest version. End of that discussion. Hope this helps!