We constantly are uploading lists that are already in the system and then letting a duplicate catcher merge them together. Instead of using smart lists from our Salesforce database, because of our complexities, I have to pull a list out of Salesforce to do some manual cross-reference and then split it into the desired segments before uploading it. I just can't get all of the necessary complexities within Marketo (it's not a bad thing, we just have really targeted needs). So, I had a heart attack this morning when I uploaded a list as usual and didn't notice the change. Then I couldn't figure out why the import finished and my list had 0 records! It probably took me an hour or more to figure out what was different. I'm fine with the change, but I'd love to have the flexibility to set that to my preferred default.