I am trying to just be honest. The 30fps should not be noticeable on a 4 inch screen from your average viewing distance. A lot of video games for the ps3 and xbox are capped at 30fps, there is no difference between how they display a 30fps game and how your phone displays it. None. If it is a non issue for ps3 and xbox it is a non issue for the htc evo.
You keep going back to the TV/Video game analogy like it is proving your point. As if it is the same thing. I argue that it is not.
It seems to me that your argument is that these two devices are proportionate (ok, they are) and that you interact with them in the same way to create the same results (this is not true). When scrolling across your phone's little screen, how easy/often do you scroll through the entire screen width? What about when playing a video game?
I don't know about you, but I scroll through the entire screen width/length of my phone every time that I swipe through my home screens, or scroll a web page, or scroll my app drawer, or drop my notification bar, or scroll through photos, etc... While I am doing this, I am looking to either reach the extreme end of the scrolling limit (bottom/top of the page), or I am trying to skim text or focus on a certain point such as an icon. Then once I see it, I can immediately touch anywhere on the screen to access what I need. So all of this entails a
very fast and accurate interaction.
How often do you scroll through the entire screen width/length when playing a video game? Assuming the typical first person perspective (such as with Halo) has a viewing area of about 90degrees, you will scroll the entire TV screen viewing area once if you make a 90degree turn. Or you can scroll the entire viewing area twice if you make a 180degree turn. Now, when you are scrolling, do you have to be able to read? Or do you have to look for the giant figure of your enemy as he's closing in on you? This requires a
very fast, but not accurate interaction.
So now you say "what if it's someone shooting at you from a distance?" Glad you asked. In that situation, assuming you are not running for cover and instead you are trying to quickly react and fire back, sure you will turn a maximum of 180degrees (two screen widths) really quick. But then you then have to slow down with your joysticks and fine tune your crosshairs to the point you are looking for (remember, you cannot just instantly touch the area of the screen that you want). So this situation requires
much slower but not accurate interaction. Unless you are good enough to spin and fire on-the-fly. In this case your accuracy suffers dramatically due to the FPS cap. Give it a try on a small stationary target. This action requires a
very fast and accurate interaction, the same as with your phone. You could swear that you hit it as you spin, but you will most often miss it because of the frame rate giving you inaccurate information about when/where you actually fired.
These situations are now matched up and show your key differences in how the 30FPS cap is perceived. HOWEVER, keep in mind that in the video game you are not constantly spinning in circles, causing your entire screen width to scroll repeatedly... that is assuming if you are any good at your game. But when using your phone, this is exactly what you are doing.
Because the phone often requires (or could at least heavily benefit from) a much more finely tuned interaction than a video game, I argue that the FPS cap can make a very big difference much much much more often. And the video game analogy does not usually apply, though it is observable in situations where you are interacting in a way that is graphically intensive (in a way that exploits the FPS shortcomings).
Edit: I feel the need to clarify that I do not believe the FPS cap causes hard stuttering/choppiness in the way that many others are suggesting. I believe the FPS cap is hindering the ability of the eye to easily follow something that is in motion... if that makes sense...
