@sans2012....agreed, there is a visible difference....but it is very small.  But as I indicated in order to get twice the resolution you need four times the sensor size!  In addition, I think any visible resolution gain with the addition of 4MP is lost due to the fact that the 10MP sensor accentuates more noise because of tighter pixel spacing (remember the sensor itself is the same size).

With regard to printing....

A 6MP image at 100dpi...gives you 30 inches by 20 inches.

A 10 MP image at 100dpi...gives you 39 inches by 26 inches.

A 6MP image at 300dpi...gives you 10 inches by 6.7 inches.

A 10 MP image at 300 dpi...gives you 12.9 inches by 8.6 inches.

Only with dramatic up-resing would you gain a significant  advantage.

In youth, we learn....with age, we understand.