:welcome
Unfortunately there is no stright answer, each game reacts differently, I would recommend checking out the
comparison screenshots and the
games list to see other detailed reports.
The reason for this is that some games scale to different ratios really well, where as others stretch to the required ratio.
Some games may draw the extra 'up&down' view, however others would scale the ratio to fill the screen so that even tho you have more 'up&down' you may not see any more of the map/enviroment, effectively the same image but at a higer resolution.
Bit like how a 2048x1152(16:9) display would effectively be showing the same enviroment as a 1920x1080(16:9) display, but just at a higer resolution making the enviroment more crisp in detail, rather than expanding the virtual viewable aera.
On the flip side, a 1920x1200(16:10) may end up displaying the same up&down viewable aera, but may in fact loose on width viewable aera when compared to say a 1920x1080(16:9).
Ultimately it really depends on the game in question.