One turntable with two arms, or two turntables with one each - which would you prefer?

@dogberry It is not madness to have a plan in mind for Four Tonearms, it is a little unusual to have four in use consecutively, but definitely not unusual to own Four Tonearms and a selection of usable Cart's to match that number or more even. 

I have owned and used approx' Nine Tonearms to get to the place I am today with a Tonearm.

Today with only one Tonearm in use, I still have a selection of Seven retained, along with LOMC, HOMC and MM Cart's, all with a usable number of hours left on a Stylus. I don't know how ageism may be affecting some through the time in storage.  

As for the offer for the Permali, the offer is for a piece of the size that would be able to be turned into a Tonearm Pod, that by design, when finished will be able to be stored in a cupboard when not in use, or only be as intrusive as a Black Brass, if kept in use. 

A Slab to not be accepted by SWMBO will be very expensive to send onto you.

I was given my own room without any dispute for the HiFi, it was like an approval to go off the scale with madness. To get the idea, the Power Amps are seated on a 250Kg slab of Granite. In the Room I would refer to that one as adventurous.

There are more quirks to be found. 

I am also an owner of Manufactured Stone as a Plinth, which has the Brand Name Corian. 

Corian is about 1/3 resin 2/3 mineral.

Engineered quartz stone is 95% quartz  / 5% resin.

These materials are quite different. I would never describe corian as a manufactured stone.

Corian is potentially the earliest form of a Composite Stone to be produced an available mainstream material, it has a Patent, and it is this Patent that is the fundamental guidance referenced to produce alternative Composite Stone products that followed.

It is hard to see how a 66% inclusion of Bauxite Stone with the rest as an Adhesive Resin, used in the mixture for Corian, disqualifies it from being termed as a Manufactured/Engineered Stone. 

One TT with one arm and one cart  . Why complicate life. Enjoy the MUSIC. Good sounding music is enough, you done need perfect sounding music as there is no sich thing

I must admit I have not heard the Panzerholz warps. Thinner thicknesses can bow but I've never seen it warp. 

We use it for professional motorsports and never had a part returned because it warp. We have been using densified wood for a few decades so have some experience. 

We have racks of this material from 3mm-100mm and have used it in many applications. 

Currently I'm building a three teir component rack with 40mm Panzerholz.