Second, I'll quote what I believe should be the end of our 'disagreement' - an agreement, imo, based on the original point...

: mechs are niche systems, suitable for a narrow and short range
: of applications. The problem is that, in fiction, they are never limited
: to those niche systems. If they aren't there for the rule of cool or
: serving as the first and last answer to anything on the battlefield,
: they're there just because... well, we've looped back to the rule of cool.
: Which also encompasses the "First and last answer" option.

Point being - my impression was that you were saying non-humanoid vehicles will always be better than mechs. But here, I think we can agree that that's not the case; to whatever degree you mean. And so, all that's left below are discussions entirely in the realm of fiction, in various subjective contexts of feasibility, believability, and preference ;)

:: But anyway, who says center of balance is
:: inherently a positive or negative, IF engineering made sure the center of
:: balance was in an optimal location for the mech already? CoB shouldn't be
:: a problem in a good design .
: It's already a problem because you have to design around it.

Every property of some machine is something to design around. It's not positive or negative until it's given a practical context. Center of balance isn't a "problem" until the machine is put in a position where it is a problem. You're framing your point unfairly against mechs. There may be more situations where CoB is a problem than where it isn't, but that's not the same as saying it Is a problem. So it comes back to whether there are situations where mechs are more useful than non-humanoid vehicles. (which you ceded above)

: Space magic is space magic because exists without regard to rules or internal
: consistency.
: The Mass Effect isn't space magic, because what it can do is very well
: defined.

erm, then we have different ideas of what defines 'space magic'. If something can't be done now - whether 'logical' or based on sound science or not, I consider that "space magic", however believable or feasible. It only works because the writers say it works, with no practical demonstration that it can or will. Extrapolating forward from good science - extending knowledge into an unknown context - is space magic. At least, that was how I was using the term. :P

: I'm arguing that those applications are niche, and rarely the roles that
: mechs are depicted in.

Then we have no further debate on my part (on what started this line of the thread at least :)

: Does human physiology have advantages? Oh, sure, compared to animals and
: simple machines, we have an advantage.

: Good against the living is one thing. Good against the machine? That's
: something else.

meh, different properties of entities that are built to accomplish some feat or feats, specialized or general. All different contexts and purposes, whether biological or not. Then we start to get into the line between human and machine; android, robot, cyborg, yadda yadda. Where would you draw the line? I'm only arguing contexts of a tool - whether human, machine, or physical enhancement of any sort. A tool. Specialized or generic. Biped or winged. Wheeled or tracked. Piloted or automated. All are simply properties, none are strengths or weaknesses until placed in a practical situation.

: While I was typing this, I saw a spider walking across the floor. I
: had to make the choice of watching it closely to study how it moves, or
: not weirding out rest of the people in the room.

Science!!

: That ain't a mech. It's a guy in power armor. Unless it's a robot or a drone,
: like the Hammeroids in Iron Man 2.

Apples & oranges. :P (from what I'm arguing - not labels but practical uses of vehicular tools)

: What's the difference between fictional technology and space magic?
: My initial position was that space magic stretches the reader's suspension of
: disbelief to the breaking point. Later, I considered Arthur C. Clarke's
: Third Law, where 'Any sufficiently advanced technology is
: indistinguishable from magic."

: I think the best place to put the dividing line between 'sufficiently' and
: 'insufficiently' is the point where we can relate to technology. Which
: still isn't a good definition, but it's a start.
: In Halo, the UNSC has some "Sufficiently advanced technology" in
: the form of shields, artificial intelligence, and faster than light
: travel. Invariably, such technology has been depicted as rare and
: expensive.

I don't see "sufficiently advanced" as a maximum limit, but a minimum limit. Once it's past a certain point of advancement, it becomes magic. I suppose that limit is what's up for debate. Is the line drawn at current technology? Or current technology plus an increase of a property that is still feasible in theory? (eg, give it more power, which we don't have currently, and you'll be able to do not just X, but Y and Z) Or the implementation of a fantasy technology that does not exist, and only exists as a some form of 'potential' future ability? Or something like that... I'm sure I'm not using the best words :P

: Telekinesis. Same place he gets his super-strength from.

http://io9.com/5810945/the-physics-of-superman

http://www.neatorama.com/2013/06/14/Physics-Question-What-Would-Happen-if-Superman-Punched-You

etc :) fun stuff

: Mostly to avert homogeneity among science fiction franchises.
: While we're on that subject, can I get a science fiction universe that
: doesn't slavishly copy space battles from Star Wars and Star Trek?

Yes please.

: Apples and oranges.

How do you like them oranges?

As for everything else, either I think the points are somewhat addressed above, or I'm just too tired to keep typing this long reply :) (this page has been sitting open all day, waiting for me to compose and complete this reply; lazy day for brainy replies)

: It's kind of a pale shade of anti-Octarine, really. That's why storytelling
: is so magical, because it relies on suspension of disbelief.

Space magic!

: Could be interesting, but I was under the impression that Paramount wasn't
: going to green-light any TV shows while Abrams was doing his movies. Have
: you heard differently?

Saw an article recently with Dorn talking about it. I believe it's moving forward, but I haven't researched to check.

: Then get that same group of engineers, and see if they can come up with a
: conventional vehicle that can do the same thing with a lower manufacturing
: cost and a higher reliability rating.

Travel to the future first, when mechs are as feasible to create as vehicles, with knowledgeable, professional mech engineers, then ask me again.

*collapses*
actually... *leaves for a special nerd nite with food, alcohol, tornados and sharks*