FOV and aspect ratio... not the same thing.
Vert- and "16:10 friendly"... not the same thing.
Again, 1920x1200 (16:10) has more pixels than 1920x1080 (16:9), but it's still a narrower resolution. It makes sense that you "see less on the sides" because, compared to 16:9, 16:10 has "less picture on the sides".
Here's what I understood while reading various sites (I'm new to all this):
1) You will "see less on the sides" in 16:10 (compared to 16:9)
only if the game is Hor+. And both 16:10 and 16:9 will show the same vertically.
2) However if the game is Ver-, both 16:10 and 16:9 will show the same on the sides (horizontally), but 16:10 will show more vertically than 16:9.
In the event that 1) and 2) are right (everyone's more than welcome to correct me), and that I'm interested in buying a 16:10 monitor, here's my original question: Can some games be switched/hacked/edited to go from Hor+ to Ver- ?
I suppose that for such a switch to occur, the game has to already know (encoded by the programmers) how much to show horizontally in Ver-. Or that such a "value" can be assigned by the user.