Just for the record, the human eye samples at an average of 70 times per second. Do note that as some first-person-shooters will attest, there are situations in which you will notice the difference between 70 FPS and 120 FPS. This is because of what's known as the FIGHT-OR-FLIGHT reflex, triggered by adrenaline. Caffeine will have the same effect, to less of a degree.
As a defense mechanism, adrenaline boosts your perception and reaction time, and allows your eyes to sample more images per second. This effect is temporary: even with caffeine. What most people will notice when their cards hit 120 FPS is minimum FPS, not max. A game that runs at 120 max FPS will likely have a solid 40+ FPS at minimum, which isn't considerably choppy by most standards.
Also note that the way the human mind blurs images to crate motion (or the illusion of) also prevents people from noticing all of the FPS and the detail within. Although the brain can sample more images under heightened reflexes, it can still only analyze and react to a certain amount, which is less than the optical sample rate. In other words, the faster your heart is pumping, the less detail you notice.
Another tid-bit of information is that the average reation time (eye-hand coordination) is 200 ms. FIGHT-OR-FLIGHT allows the body to utilize reflex actions for normal memorized patterns. A reflex is an action-reaction pair that bypasses almost all analysis. The reflex is based on a trained scenario: when X occurs, perform Y action. The better gamer (i.e. a twitch-guru 😉) is the person who is most capable of learning and adapting reflex-actions with some fair amount of post-analysis.
Just food-for-thought. The Xbox 360 version lookds great: no complaints at all. If your computer can't handle Oblivion and you're feening for it, and you have a modest home-theater, DEFINATELY get the Xbox and the xbox version. Playing Oblivion is best experienced with ambiance.
P.S. I have a widescreen and I DEFINATELY recommend it. Can you say Halo-2 peripheral vision? 😎
{Useless info for those interested in the effects of caffeine}
Caffiene is not this source of energy most see it as. The brain can speed up and slow down naturally, and does so through chemical reactions. Think back to the anti-histamine commercials with the histamine-blocker animation. The brain has receptors and chemicals that bind to those receptors, which trigger electro-chemical reactions.
Caffeine produces a chemical after it's metabolized that binds to receptors in the brain that trigger the brain to slow-down naturally, preventing the real chemical trigger from binding to that receptor. This prevents the brain from slowing down naturally, usually causing an almost perpetual increase in brain activity. All chemical reactions in the brain use Oxygen, and thus require blood. The more work the brain does, the more blood it needs. This demand for blood increases the heart rate. This is why caffiene increases the heart rate.
The ill-effects of caffiene show themselves because the increased work by the brain drains our system of the nutrients needed to efficiently produce ATP, the body's natural energy. We might have enough raw energy (Such as carbohydrates), but lack the catalysts to convert them. The body does a great job of simulating certain chemicals we lack to prevent a system shut-down (per se), but that's why a lot of us yawn at 3:00 in the afternoon without feeling at all fatigued: we're not out of energy, we're just out of ways to use it.
Make sure you take a multi-vitamin if you drink a lot of caffeine. Some believe excessive caffiene intake is linked to Chronic-Fatigue-Syndrome.
[End of useless info]