All great feedback, thanks! Some quick replies:
- The omission of '<>' from the operator list was just an embarrassing mistake on my part. #facepalm #WILLFIX
- Also agree that a drop-down list of checkboxes (ideally a searchable one!) with an 'in' operator for low cardinality columns would be great. But the UI for that is a bit involved, and probably also need to provide some user control over when to do this since gathering distinct values can be an expensive operation for large data sets.
- Totally agree that it would be useful to provide more interesting column stats.
Thanks for the suggestions and refs to other tools -- very helpful.