Yes NVIDIA 3D Vision isn't a gimmick it really Is amazing, not only in terms of immersion but in terms of depth perception, spacial awareness, closing-in speeds, etc.
The reason why many of you guys are getting such low FOVs (like 14 degrees) is because you must either have tiny monitors or you must be sitting extremely far away. A very high FOV relative to what your proper FOV should be is just making everything on the screen tiny compared to how large that object should look to you in real-life.
On a single screen, over a period of a few months, I slowly brought my FOV, little by little, down to about 30 degrees. The perfect FOV for my setup (eyes are 30 inches away from a 24 inch 16:9 monitor) is 17.5 degrees, however I don't quite go that low, I compensate and use 25.
For the peripheral vision...well that's where triple screen monitors come into play. Also, remember that the larger your monitor and the closer you are to it then the higher your 1:1 true-to-life in-game FOV will be.
With a high FOV corners look ridiculously straight, elevation changes look ridiculously un-steep, and things will look like they are super far from you and coming to you at 700 mph. Basically everything is distorted from how it should look to a human. Once you bring the FOV to a 1:1 representation of real-life, or close to it, then you'll see just how sharp some corners are, you won't wonder why you understeered into the wall going through a corner that didn't look sharp, you'll be able to use tiny trackside objects as reference points that you could hardly spot while using a high FOV (one time in real-life F2000 I used a dandelion flower for a braking marker, good luck being able to spot a dandelion with a distorted, squished, and unrealistic high FOV).
Should really check out these discussions
http://www.racedepartment.com/threads/setting-up-your-rfactor-fov-tutorial.16847/
http://isiforums.net/f/showthread.php/93-Setting-up-your-rFactor-FOV-Tutorial
http://www.nogripracing.com/forum/showthread.php?p=1160743