Are linear tracking arms better than pivoted arms?

In general ( terrible term in itself.... ) the horizontal moving mass of all tangential ( linear ) tonearms is much higher than with any pivot tonearm.
The armpipe of the linear tonearm first needs to be deviated from the zero error line to move. then the whole assembly with the bearing/housing moves. It does so by the lever of the armpipe ( reason for short pipes with Versa Dynamics and Souther - but they have other problems, due to this super short armpipe). All this force - the force needed to move the whole tonearm - is applied at the stylus/cantilever/suspension of the cartridge.
The passive linear tracking tonearm needs kind of negative feedback loop to move forward.
The lever only acts when there is an error first.
I think anyone can illustrate the situation in a minute on a sheet of paper with the force vectors - it really nice clarifies the point.
The movement of the linear tonearm is a chain of error-correction-error-correction. The force takes action at the stylus first and declines the cantilever - then the armpipe follows with the bearing/housing behind.
Not a healthy situation for any cartridge.
I love the principle of linear tracking due to its theoretical advantage of zero tracking error. Its just that in the experience working with the various designs offered to the audiophile in the past 4 decades since the Rabco saw the light of day, none could overcome the inherent mechanical problems which ultimately nulls and voids the theoretical advantages in the long term.
A problematic situation for the cartridge (a working situation it was not designed for...). A problematic situation for the energy transfer abilities of the tonearm due to anything, but a tight, rigid bearing ( in real world ).
I would love to see a linear tonearm fulfilling the promises of the theoretical basic concept.
But zero tracking error is not everything in tonearm design.
Once minimized, there are several other aspects which too do have strong influence to the sonic quality of the performance.

Dear Pryso - as a more direct answer to your question 02-22-10 directed to me - the "stress" on the cantilever mounted in a pivot tonearm (if we leave skating-force aside for a moment and address the force vector only, which promotes the movement of the tonearm.. ) is very different from the one applied by guiding a linear tracker.
The derivation force in the linear tracker adds a force to the stylus which is about 90 degrees off - i.e. in the linear line - towards the "normal" (read: in pivot tonearm) force which does (normally...) point towards the pivot point of the tonearm.
The cartridge and its cantilever ( every cartridge - even DECCA/London and IKEDA with their "string" holding the "vertical" cantilever or arc in position) are designed to address that ("normal") force only and thats why that "linear derivation force" in a linear tracker puts indeed - no matter how careful set-up, leveled etc. - an additional stress on the cantilever/suspension system.
And it does so in a way the cartridge was not designed for to withstand for long.
A short sketch on white paper will immediately illustrate the forces and the dilemma.

Remembers me to the day from my good old times when I was asked after listening to the Goldmund Reference with the T3F Arm which Cartridge I would mount in that Arm? Goldfinger, UNIverse, Olympos or even something more expensive????
My answer was "Go for the cheapest one or to that one you hate most".
I saw the movements from that Arm and the smeared soundstage was one of the results.
But honestly, I guess, that was not the answer the other one wanted to hear :-)

Excentric records kill all theoretical advantages of passive linear trackers. Doing simple math, you can see a side force as large as up to 1.0 gramm peak applied to the cantilever when say, 200 gramm of slider+arm mass is driven by 1 mm out-of-center record. Cantilever ealisy moves more than 1 degree from centerline under such force. In perfect world of ideal records, when the arm moves accross the record with virtually no acceleration, high lateral mass is a good thing, allowing needle to follow groves while the arm stays steady due to high inertia. From my personal experience with 120 g air tracker, 1-1.5 mm eccentricity is pretty audible, not to mention lead-out groove, where cantilever bouncing becomes scary.

Well, after starting this thread and reading everything everyone has written, I have decided to give pivoted arms another shot. After numerous emails with Dertonarm, I have decided to buy a Fidelity Research FR64s tonearm. I know Raul thinks the AT is superior, but based on its low resale value, I decided against it. If for some reason I decide I don't like the FR, I am confident I can get my money back. I am looking forward to all of the parts coming in (I bought the arm, a new TNT armboard from VPI, and a NOS Orsonics headshell). It is my hope that this combo will sound better than my ET-2 in all parameters. If it does, I will gladly sell the ET-2 and be done with linear tracking arms once and for all. Since the arm is coming from Australia, the headshell from Hong Kong, and the armboard from VPI, it will be awhile before everything arrives. It should be interesting and I hope worthwhile. There must be a reason why the FR64s has a cult following and the value continues to climb.