[Number 6]

...the G19?



Or the G26?



My guess is that the MP9c is smaller than the G19 but slightly bigger than the G26 in some dimensions.

 

[m4arc]

The G26 and the M&P40c would be closer to the G27.

 

[Mike]

The G26 is the closest. The 9c is 7/16" longer, and about 2 oz. heavier W/O mag. They are the same width & height.