What innovative, unconventional cartridge designs can you recommend?

@richardbrand pops and clicks are less audible with DS003 most likely due to the line contact stylus shape. Pops and clicks tend to live closer to the surface rather than in the groove, unless you have a record that was played way too many times or played on a bad set up that caused damage to the grooves. It might not have as much to do with type of cartridge being optical. Pretty sure the lower model DS audio with shibata stylus would be noisier than your ds003. 
 

RB, MI type cartridges can have high output, albeit not in the level of an optical, with moving mass lower than MC, and therefore are very quiet, with an ancillary dependence upon stylus shape. MI cartridges and their like have lowest moving mass, not MC. I guess I have said this before.  Sorry.

@audphile1 

Pretty sure the lower model DS audio with shibata stylus would be noisier than your ds003

That's exactly why I went one notch up the scale. 

My Micro-line styli are excellent at bridging wear gaps in the groove on my old records.

But everything I read says the optical mechanism has a lot to do with noise reduction.  Imagine driving down an Australian bush track with the occasional pothole or rock.  Hit one of them, and there is a momentary jolt (rapid change of velocity) but not much change in position.  Electromagnetic cartridges respond to velocity, whereas optical respond to position.

Sooner or later, to continue this discussion sensibly, you are going to have to get your hands on an optical cartridge plus Equalizer, and I am going to have to get a Moving Coil.  Who will be going backwards?

@lewm 

I guess I have said this before.  Sorry.

No need to apologize for repetition in this thread!

Are there Moving Iron designs other than Decca and its direct derivatives worth considering?  Serious question.

Prima facie, iron is a very dense material to attach to a stylus, compared with Beryllium, Boron, Carbon and even Aluminium.  But it is slightly better than Copper

I think it would be more accurate to say that optical cartridges respond to displacement, rather than to "position".  It's the distance the stylus tip moves (for optical and strain gauge) vs the velocity at which it moves (for electromagnetic).

I apologize for the following, but what the heck, I am waiting for dinner:  On p. 8, you wrote, referring to me, "Earlier in this thread you posted calculations giving the capacitance required to smooth various output voltages.  With respect, your formulae did not factor in the acceptable ripple level on the output.  Adding more capacitance asymptotically reduces ripple and in that sense you are only subject to the law of diminishing returns in terms of cost, weight, volume."  Unless in fact you are referring to someone else, all I ever said was that the amount of capacitance required in a PS is inversely proportional to the VDC delivered to the circuit.  I did not post any formulae. And yes, one can go crazy with capacitance above and beyond what is really necessary to achieve DC.  In part, the excess capacitance makes the PS faster to deliver current if it is suddenly needed. However, that does not apply in Class A circuits or probably for the cartridge.