Look at some of Bill's data:
Note that if you shift along the X axis the relative performance changes. This means that any observations you make without measuring and equalizing flow for every block will be totally system dependent (same pump, same rad, same fans, same tubing size/length/routing) and not of much general use.
So you could say "in MY setup at this moment block A is best", but making any changes that affect flow rates will make this statement potentially false.
That is why flow rates should be measured for testing. If you know the pump/rad that you plan on using then you can choose a block more appropriately if pressure drop and performance curves as a function of flow rate are available.