> In the digital realm, anything capable of handling the signal should be as 
> good as any other,

Unless it is *only just* capable of handling the signal, in which case any 
additional interference (eg you put a new device or another cable next to 
the HDMI cable or receiver, a car drives past, someone turns on a motor, 
etc) and then it will stop working.  I have never seen anything like this 
though, even my $10 5 meter DVI->HDMI cable has worked flawlessy at 1080p 
while being tangled up behind 100 other cables behind my computer and TV.

> the higher bandwidth might be necesary.  But for now, what good is it?

It's always good to have a little in reserve, as explained above, but really 
I suspect the ultra cheap ones have plenty enough in reserve.  The shops 
that you go to of course are going to stock the expensive ones, as they 
would prefer to make $20 profit on an $80 cable than $2 on an $8 one. 
Magazine reviews are also biased because the makers of the $100 cables send 
them loads for free, if the magazine writes bad reviews about them being a 
waste of money they likely will not get any more.

> In fact, I'm still not convinced that 120Hz LCD makes any sense 
> whatsoever.  With CRT's, it made a LOT of difference, because it 
> substantially reduced flicker.  LCD doesn't have flicker.  It has response 
> times, and lowering the response times does make a difference.  I'm not 
> convinced that a 5ms 60Hz screen would be any different from a 5ms 120Hz 
> screen, or even a 5ms 240Hz screen.

When your eye tracks a moving object on an LCD you see blur for two reasons. 
One is the response time of the pixel, the other is the fact that the LCD is 
finite resolution and the frames are displayed continuously (and not as 
impulses like a CRT).  Even with a response time of 0ms you will still see 
image blur.

Recently the LC technology has improved giving faster switching times.  This 
has two impacts, it means the 2nd type of blur I mentioned above becomes 
more apparent, and that it's possible to refresh at higher than 60 Hz.

Given the very fast response time, the easiest easiest way to reduce blur is 
to simply show a totally black frame between each real frame.  In theory you 
could make an LCD perform like a CRT by only showing the frame for the first 
5-10% of the frame, then showing black for the rest of it.  Recently with 
LED backlights it is becoming very easy to do this sort of thing (LEDs don't 
care if they are at 100% brightness 100% of the time, or 1000% brightness 
for 10% of the time).

As already mentioned, it makes an even better effect if the TV can 
intelligently calculate some "inbetween" frames to display.  This has the 
disadvantage of being costly to implement and obviously not being able to 
predict everything perfectly.  But mostly the result is visually superior to 
simple black frame insertion.

BTW I would suggest comparing fast scrolling text (eg end credits of a TV 
show) on a normal TV and a 120 / 240 Hz version - the difference is obvious.

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