Of course there is some effect to having the top monster.
The real question is -
how big is the effect?
My wife is a graphical designer and has a company that deals a lot with branding. So we have had quite a few scientist vs designer discussions over the breakfast table over the years.
And one thing is sure - branding has effect, a specific occurence such as this has smaller effect, and the value is always situational.
The original poster had valid points. Either you don't care, and you buy what's inside/recommended, or you care, and then you are bound to realize that there are different cards, and what you are buying is not the heaviest hitter. Also, we have very recent empirical evidence of ATI having the arguably fastest offering in the X19x0XTX for a reasonable period of time, and still having their marketshare eroding horribly, indicating that if the halo effect is there, it is pretty weak.
That is not unique to graphics cards btw - Mercedes Benz has a good brand, but that doesn't make their compact car sell like hotcakes to people believing they get a bargain.
There are a couple of factors however that could make the shine of having the fastest card strenghten the other products in the line. The most important is probably the suggestion that there
is a halo effect. So if nVidia talks with Dell, they will point to the charts and say "we're at the top, consumers see us at the top, and nVidia is the brand they will prefer, so it's in your best interest that you offer our products!". And that might turn out to be a relevant bargaining chip, leading to high volume sales. Note that whether the end user actually buys into this line or not is irrelevant as long as the Dell negotiator feels that the end user
might. And I think this thread amply demonstrates that the "I'm smart, but the rest of the world are idiots!" mentality is well spread.
And probably applies to Dell/HP/etc product strategists as well.
I have made no secret of the fact that I think the focus on "the fastest" in enthusiast tech publishing is exaggerated and strengthen problematic trends. Yes it interesting, but is it really all that interesting or important? I don't think so. But then again what is the industry going to hype otherwise? Well, as long as the marketeers assume that their customers are pea-brained young males, they could try for even bigger boobies on the packaging, and in fact they do so. Along with Hyper-super-XTX-Ultra-Golden Sample naming, which is also used by all players, indicating what level of customer they assume they address. Hyping the fastest/biggest/noisiest (remember the dustbuster "badge of honour"!) of anything is very very simple marketing....
Neither me nor my wife, (I asked her although her lack of interest was monumental), can see any reasonable way to actually assess the importance of the halo effect, other than noting that what feeble empirical data exists doesn't indicate that it's very strong.