I don't know the technical ins and outs surrounding ceramic coating - as you say Scott, google will probably fill you in on that.
However I had my A6 ceramic coated by a "professional detailer" at significant cost - not a main dealer though - and I can say the results were quite impressive.
I, like yourself, take pride in my cars - and keeping them clean, and polished and waxed. The A6 was always kept clean and had around 2-3 thin layers of wax on.
However being black, the more I washed (no matter how safely) I still incurred swirl marks, and found contaminants such as tar was stick and require some form of clay bar or tar remover to clean off, no matter how good my wax protection was.
The A6 had a 2-stage machine polish, which using extremely good machines and in the hands of someone who has a passion and the knowledge for using them, is worth the money IMO on its own. Getting the foundations right are a must! and with the bodywork as good and contaminant / swirl free as it could be I had two layers of ceramic coating applied.
These bond to the paintwork and as the name suggest, use a chemical layer of coatings that "claim" to be as hard as ceramic. My understanding is that this means not only do they bond better, but "seal" the paint thus creating the tight beads we all dream off (or maybe just me!
) as the water cannot lay in the un-flat imperfect paintwork due to the layer of coatings.
Being harder than wax, the ceramic coating also lessens the effect of swirls being created through improper washing, and or stone flicks, rub marks e.t.c. Generally its harder so scratches less.
Wax layers can then be applied to a cured ceramic coating also, which provides a strong base layer for the wax to bond to.
I certainly found on the A6 that even when my wax layers on top of the ceramic coatings had diminished, the ceramic coating still beaded nicely, and the paint was remarkably less covered in swirl marks considering the frequency I washed it.
Does ceramic coating scratch - yes! but it takes more effort for everyday routines to do so in my experience.
I have recently tried to apply the AutoFinnese ceramics range to the Q5 - giving it a very good machine first, and then following the instructions supplied with each product. I was dissapointed! The window ceramic coating has lasted well - still beading nicely. But the paintwork ceramic hasn't - certainly compared to my A6!
This could be down to the chemical make up of the ceramic used - for instance the autofinesse bodywork is around £40-£50. The Miyabi / ISM ceramic coatings used on my A6 are around £250.
In short - I believe applied by someone who can get the paintwork looking as it should - ANY coating will suffice to protect, but ceramics seem to have the advantage when it comes to longevity, and protection, but are really only as good as the people who apply it, and what product is actually applied.
Great thread though - interested to see other peoples views...