The discussion and analysis in Dale Myers' article is very good, although someone who just reads the headline could very easily come away with the wrong impression.
The "older" .agilekeychain format (AKF) — designed nearly a decade ago – does indeed expose the same sorts of information that would be in someone's browser bookmarks. So if someone gets hold of your AKF data they will be able to see what sites you have Logins for and what titles you have for your items.
Given the constraints we faced back then, that might have been a reasonable design choice at the time. But it is certainly not an acceptable design choice today.
The article does point out that that the OPVault data format was introduced as a replacement for the AKF back in December 2012. The OPVault format not only encrypts much more of the metadata, but it also provides for authenticated encryption and includes many other improvements.
The article also points out that the behavior of the AKF "discovered" is documented in many places. We've blogged about it, we've talked about it on our discussion forums and it is in the docs. What isn't in place is some big red letters in the user interface that says "Using this format leaves URLs and Titles unencrypted".
Dale Myers' article also correctly points out that we do offer instructions on how to migrate your data from the Agile Keychain format to OPVault.
The article criticizes us for (a) Not making OPVault the default for new Dropbox synching, and (b) Not providing a nice easy way to migrate
Obviously we would love to see everyone on the new data format. It is a big improvement over the old one in an enormous number of respects, but until we can be confident that everyone is running clients on all of their platforms that can handle the new format, we are treating migration as an "expert only" thing.
Rolling out a data format change when you have one "product" and one platform is easy. But we need to make make sure that people are using versions (and that such versions are available) of 1Password that handle the new format on all of the devices that they sync with.
So if we were to make OPVault the default sync format on Mac, we would need to know that the 1Password app people are using on Windows. We have been conservative about this.
Also, in our beta testing of data migration, we discovered a nasty bug in how we encoded keys for the some attachments. The result is that some of our beta testers would have lost data if they had not had good backups of their AKF data. Obviously, that is not something we wanted to push into general release. (Only attachments created in specific circumstances were victims of that, so we didn't spot it in internal testing.)
Now you may very well disagree with some of our judgement calls, particularly about how cautious we have been and continue to be in migrating people to the new format. But I hope that even if you do disagree, you will see that there are reasons for our choices.