Here are Mazda sales according to goodcarbadcar.net, both the Mazda3 and CX-5 are outselling the Mazda6 so far in 2014 (1st column is ytd July 2014, 2nd column is ytd July 2013, 3rd column is 2013-2014 change, 4th column is July 2014, 5th column is July 2013, 6th colum is 2013-2014 July change):
#46 Mazda 3 61,529 61,937 -0.7% 9381 9236 1.6%
#50 Mazda CX-5 59,384 45,880 29.4% 9109 7825 16.4%
#85 Mazda 6 31,967 25,115 27.3% 5049 3447 46.5%
#149 Mazda CX-9 10,931 16,756 -34.8% 1678 2084 -19.5%
#157 Mazda 2 10,032 6394 56.9% 2075 800 159%
#170 Mazda 5 8762 10,023 -12.6% 1547 922 67.8%
#211 Mazda MX-5 Miata 3062 3812 -19.7% 399 663 -39.8%
See table at http://www.goodcarbadcar.net/2014/08/usa-auto-sales-rankings-by-make-model-july-2014-ytd-sales-figures.html for information of all brands.
Edit:
I agree with your analyses on the Mazda6 and the Mazda3. While being smaller than the Mazda6, the Mazda3 is much sportier. For me, the Mazda was the best combination of efficiency, sportiness, luxury, and cargo carrying ability of all the cars I looked at. It won my my heart.
Congrats on your choice. It seems the best for what you were looking for.