The human eye can only distinguish and interpret 29.1 frames per second. So yes, 24 would appear jittery at times, but only during explosions or large particles. It's a known fact that Crysis wasn't exactly optimized the best. Not to mention, not all games play the same. It heavily depends on whether or not the developer optimized the game correctly. For example, Call of Duty games are well known for their optimization (when Infinity Ward makes the game, that is). However, Sim City Societies ran like garbage even on the most top of the line computers. Minecraft is another example. Minecraft has graphics, but due to it being optimized poorly, on top of having a custom terrain generation every step (not a bad idea in theory, but terrible in practice), makes it one hell of a laggy game at times.
As for graphics cards, I've NEVER seen any card review that used Metro 2033 as a "benchmark" for a card. I've seen Crysis, but never Metro 2033. Crysis, again, was rather poorly optimized, so unless you have dual SLI / CrossFire cards, chances are it's going to run like crap on even the highest systems. And face it, not many people have $700 to be throwing around for dual graphics cards. The HD 4650 isn't "crap" just because it can't play Crysis, the HD line of cards are geared towards media box's more than anything. I strongly advise against ever using ATI cards to begin with, due to poor driver support.
In the world of dual / quad core processing, 2.5 GHz isn't bad. In all honesty, they could do away with including the clock rate, because most people see it as an upper hand. If clock rate was so important, why is it that you can find a dual core 1.8 GHz more expensive than a Pentium IV 3.2 GHz? Because in this day, it's irrelevant. The clock rate measure was primarily to measure single cores. I can play Crysis on low on my HP NC6400, which has a 1.8 GHz processor, and Intel GMA 950 integrated graphics. That doesn't really say much for people who invest thousands in gaming desktops, when a 3 year old laptop can play a game that many budget builds simply cannot.
In regards to your overclocking claims, you've obviously got no idea what overclocking does. First, cooling is only part of what you need to do in order to make sure you're running a stable overclocked build. Cooling is the bare minimum. You also need to know about your processor architecture, its limits, etc. All too many times I have friends and family coming to me asking me why their computer won't start / runs very slow after they tried overclocking it. Most people jack it up as high as possible, which is EXTREMELY unstable. You're only supposed to overclock a small amount, not a huge extreme. Again, if your build is far superior to any other budget build, why would you need to overclock it?
As for found cheaper, you're 100% correct. If you go into any commercial store, they don't even sell cheap gaming budget builds (your PC in reality is a budget build), simply because they are selling NAME BRANDED COMPUTERS. Instead of selling PC's that are made of all different parts and such, such as custom builds, they sell a general PC package with everything thrown together for you. Most people work with this, because most people don't participate in development / competitive gaming.
As for everyone being able to build a computer, I agree. Most people can't. Most people couldn't tell you one thing about computer hardware, which is why your builds would be good for people, but you're targeting a largely hardware based community, meaning most of us floating around these forums generally know how to assemble a computer. As for shipping, I paid $30 to have my PC + parts shipped to me. I built my rig with about $940, but that's because I put in some better hardware. Regardless, the same build would cost me $1320 if I bought one pre-built. As for "time and labor", it's not exactly a physical or mental feat to be able to build a computer. I put in a motherboard, installed a power supply, installed a processor / thermal paste / heat sink / fan, installed the RAM, Blu-Ray drive, 2x 1tb hard disks, graphics card, wireless PCI card, and all the bits in between in 40 minutes. Sure, it can vary from time to time, but I was honestly taking my time when building to ensure all parts were installed correctly and were not broken. I'm not trying to say my PC building skills are superior to yours, because anyone who has a basic understanding of building PC's can do it, I'm simply saying "labor" isn't really even a factor in the matter. I could see if you were building over 40 PC's a day, but 1-8 (which is what I'd assume you'd be doing during a day, at most), you should be able to knock them out in a few hours.
My arguments are based on basic common knowledge. I'm not saying you're not a good choice when it comes to PC building, because you are, but only if you don't have the skills / time needed to sit down and build a PC.
I just now realized I've had a typo in my signature for the past 3 years.