Direct Drive vs. Idler Drive vs. Belt drive


I'd like to know your thoughts on the strengths and weaknesses of each drive system. I can see that direct drive is more in vogue over the last few years but is it superior to the other drive systems? I've had first-hand experiences with two out of the three drive systems but looking to learn more.
128x128scar972
@chakster thanks for that suggestion. The weight shouldn't be a problem, as the standard rubber mat is probably not much lighter. I use an Orsonic DS-500 clamp (weighing 500 grams) with the Pioneer, but could always replace it with DS-250 at half that weight to compensate if need be.

Neonknight, I feel your pain. Reasonable assessment. Which of your tables do you use the most? 
Antinn, great choice of mat. The triboelectric series you posted is upside down but it says the same thing. Materials at either far end of the series are problematic. Leather is right in the middle and has relatively neutral behavior. The problem however is that PVC is all the way at the top (in this series) And it is the material that is being rubbed into collecting electrons by the stylus not the mat. You have to discharge the record preferably while it is playing to minimize static build up and dust attraction. Interestingly paper is at the bottom and loves to donate electrons while vinyl likes to collect them. Paper is a bad choice for record sleeves But it is still the most common type of sleeve. Tells you how much the record industry cares about the longevity of their product.
Atmasphere, from an intellectual perspective I think you are right. However, the best tables have very inert platters and tonearms and you really only have to worry about their primary resonance frequencies. These are going to be so low that their impact on the sonic picture should be minimal if any at all. I have not seen any data but you would think  air bearings or opposing magnet bearings would have less rumble. Certainly less wear on the bearing but what about the compressor? I think the opposing magnet design as used by Clearaudio and SOTA is a far more elegant solution, nothing to break or wear out.   
As far as scar's question is concerned, everybody thinks what they own is the best or at least they want to convince themselves of this. There are several facts that can not be avoided. Direct drive turntables have a large spinning magnetic device right below a very sensitive magnetic device ,the cartridge. Aesthetically that is a huge problem for me even though I have never seen any non biased data to indicate that this is a problem. The Japanese make very trick products, well finished and jewel like. I think this sucks a lot of people in. There is a saying, the Chinese eat with their stomachs, the Japanese eat with their eyes. We listen with our eyes. If it looks good it must sound good. 
Idler wheel turntables have more moving parts in direct contact with the platter. They can be pretty quiet when new but will produce more rumble as these parts wear. No matter how quiet you can make an Idler wheel table you can always make a belt or direct drive quieter. IMHO belt drive is a simple low noise solution that is difficult for the other drives to out perform by any sonic measure. All the Mega priced tables are belt drive. The Air Force Zero, Basis, Clearaudio Statement are examples. When people do "cost no object" designs they always rely on belt drive. There are very few producers of idler wheel turntables today. The vast majority of them are refurbished old tables. Same is true of Direct Drive. Look at what the reviewers use as their reference tables. 
Nottingham Hyperspace has or had a very thick mat that appears to be graphite in photos, about one inch thick.
@lewm 

That's right. So did their other top tables. It actually looks like a composite of some description, but performs very much like the graphite slab on my DIY.