We use Google Sheets all the time with WP All Import, as we really like using the dynamic URL instead of downloading/uploading CSV files. The feedback that I have, is that it would be nice if WP All Import recognized the correct tab for the import instead of defaulting to the first tab. Right now, in our workflow, we always have to double-check that the table that we are importing is the first tab in Google Sheets so that WP All Import can pick it up. Seeing that every tab has a unique url. It would be nice if we didn't have to do that.

A solution was found here: https://stackoverflow.com/questions/27000699/google-spreadsheet-direct-download-link-for-only-one-sheet-as-excel

It would be nice if the plugin would automatically identify and convert the /export?format=xlsx&gid=0 link for us. I can only assume lots of other users are struggling with the same issue.