A while ago I started to sound like a broken record when saying that even if data modeling in NoSQL seems too simple to be true, in fact it is once again an art we need to master as otherwise sooner or later will start complaining about it. Well it looks like that time is starting to be now.
Brian on why he stopped using Tokyo Cabinet:
I have no idea how to use a key/value store database properly. TC will take anything you dump into it, which is both a strength and a weakness.
Some kinds of queries were still awkward in TC.
So if you still think schema-less means not data modeling, then you are doing it wrong!