Is there any difference between the EC1 (or EC2) and EC1-B (or EC2-B)?
Both the EC1 (or EC2) & EC1-B (or EC2-B) use a 3360 sensor.
The biggest difference is in the mouse feet as the EC1-B (or EC2-B) uses 4 small mouse feet, and the EC1 (or EC2) uses 2 large mouse feet. Small mouse feet provide a faster tracking feeling whereas large mouse feet provide a more stable feeling instead.
The EC-B Series is the first time we phased-in the 3360 sensor, and we got lots of feedback from pros and players that they’re not getting used to it because the tracking feeling between 3310 sensor and 3360 sensor is different. We believe that small mouse feet increases the difference in the tracking feeling.
Therefore we've changed back to 2 large mouse feet on the EC-B DIVINA Series and following EC models to make it easier for EC-A users to get used to the transition and make the EC series as stable as the old EC-A Series.