The flow is very important to me, too. Some of my favorite albums are actually portions of albums that have a continuity... until they go a certain distance and then it's gone. I've had albums that would have been perfect if it were cut by three songs. But then I would have felt cheated because the album was "short". On the other hand, I've had "double" albums are are perfect... the flow is consistent, but it was still too long. Not that I didn't appreciate all the tracks, eventually. But it seems that my attention is only good for up to an hour of music at a time, and then I want to move on. Perhaps to other music, but I'm still moving on.
How often is it that an artist can have a single artistic vision that lasts for a full 50 minutes? Isn't that pretty rare? Or is it my attention that is lost?