We'd really like to have characteristics available as a field for constituent-based queries. Currently I can only find them in grant-based queries. For example, we are putting a characteristic on the constituent record for recepient organizations that have requested grants by EFT instead of check (this is a work-around for the lack of ability to set payment defaults in individual constituent records in GE, or even better, have them connect to the defaults set in FE; there is another post here on UserVoice about this issue). So, we would like to be able to run a report to see which of our constituents have requested such. And I'm sure it would be useful for other constituent-based reports.