And your "proof" is as old as you are, because it is only you making these claims, no benchmarks, articles or anything. And yes I have tested USB 2.0 vs FireWire on my MBP in OS X and Windows, and while USB 2.0 may be slightly faster under windows than OS X, both were typically 50-60% of the speed of FW400 under either.
I did some extensive testing with my WD Passport Studio 500GB both on my MBP under Leopard using FW400, FW800 and USB 2.0 and on my PowerMac using FW400 and USB 2.0 under BOTH Tiger and Leopard and posted my results here (and got zero replies):
https://forums.macrumors.com/threads/628177/
Overall, testing showed USB 2.0 under Tiger is TERRIBLE. However, the test also showed that USB 2.0 under Leopard is pretty much fixed only slightly slower than FW400 (but does incur bandwidth issues if you have a lot of USB 2.0 devices which is far more likely than having large numbers of FW400 devices and also grabs more CPU cycle than FW400, especially on older computers like my PowerMac). FW800 wipes out either FW400 or USB 2.0 and was faster by far than my MBP's internal 5600RPM Sata.
I have no issue with using a USB 2.0 drive with my MBP, but FW800 is faster so it's moot. My older PowerMac also runs USB 2.0 fine under Leopard, but I still often use Tiger because it's more stable overall for that machine and definitely faster everywhere else and so a FW400 interface makes the most sense there. A drive like the WD Passport Studio 500 gives me all three in one and runs off the interface's power (no power cord needed), so it's the right choice for me and my setup and especially my MBP.
Thus, when you have FW800 on your Mac and you have the choice of getting a USB 2.0 drive and saving a few dollars or the FW800/400/USB2.0 version and getting VASTLY faster performance, well, the choice was easy for me. I took the FW800 model. It also works full speed in Tiger on my PowerMac using FW400 and can connect to my PC which has no Firewire using USB 2.0. But this idea that somehow Firewire is "dead" when most of the PC laptops out there have it, PCI-E cards are available for $20 (FW400) or $45 (FW800) that will add it to your existing tower PC and allow more and faster compatibility with drives that are STILL readily available from even mass market places like Best Buy is just absurd. And all drives I've seen that have Firewire also have USB 2.0 so there is no danger of losing compatibility in the future.
Thus, it's obvious that FW400 is superior to USB 2.0 in terms of performance, however slight and that FW800 wipes the floor with USB 2.0. USB 3.0 sounds great on paper thus far, but until I have a working product available to me, Firewire 800 still rules the PC world (eSata is great for HDs only) REGARDLESS of what trolls on here think. Your Mac probably comes with it so you might as well use it. Your PC might not come with it so maybe you don't care if speed is not an issue or you have eSata and no need for any expansion other than hard drives. But this is a Mac forum so most users on here DO have it and so it's still plenty relevant to them.
Whether a Mac (or even a Windows) user buys a camcorder with firewire or not is of no business or concern to someone like MosX. Let him use his USB 2.0 peripherals if that's what makes him happy, but coming here just to get into arguments with how Windows and PC hardware is superior to Macs or OS X with no other goals or reasons amounts to trolling because these are not Windows forums and they certainly are not the Mac reeducation forums by arrogant Windows users. If you want to run such a thing, go make your own forums and see how many Mac users actually join to listen to you preach at them how stupid they are for still using a Mac.