Interesting thread.
I have owned the Pioneer Exclusive P3 for quite a while and recently a SP10mk3 with mk3 plinth etc. I can't say I hear any hardness or mechanical haze with either of my vintage DD tables unless its in the recording. I am not disputing what Peter heard, as I am sure it is what he heard.
The first thing I noticed on Peter's photo of the SP10mk3 is that the Micro Seiki CU180 is on the platter upside down - that alone may been the root cause what Peter heard. The cu180 gun metal platter goes the other way and it makes is a perfect fit, like a glove that is just over the top of the platter. It is bloody hard to remove after you have set it down as it's such a snug fit.
The trouble is with anything as high end as Peter's system and the equipment, just plonking down a piece of equipment generally does not automatically give you the WOW moment - it takes quite a bit of work. Peter's system will have been painstakingly voiced around his SME table.
yes, the Technics does have more detail, but it also has more leading edge attack and instruments don't hold onto the notes as long as BD tables.
Both DD and BD can both sound superb when tweaked in your system - you choose your flavour and enjoy 
XV-1, those are two lovely turntables. Congratulations. I am not surprised that you hear none of the hardness or mechanical haze that Al M., David, and I all heard from the SP10 in my system. I have read many outstanding reports of the wonderful sound of the SP10 and it has indeed sounded much better in David's own system. These glowing reports are one reason I wanted to hear the table in my system. I was also curious if I could identify through listening a difference which I could attribute to speed accuracy and consistency. It is sounding more and more as if there was an incompatibility issue with my system or an implementation problem with the platter mat, some modification, some lack of the right modification, etc. None of these refurbished SP10s seems to have the exact same plinths, level of modifications, arms and cartridges. There are just so many variations among them.
I had no idea about the CU180 mat being upside down. That is worth David investigating. Yes, it is a very snug fit and he will need to be very carful when removing it to flip it over. That may very well solve the problem, but then again, David reports that the table sounds fine in his system, so who knows? We will investigate in time.
Your comment about the WOW moment is interesting. I understand about a component like a pair of speakers being placed in a new system requiring time to be properly positioned and broken in. Same with a new amplifier which may or may not have compatibility issues with the speaker load it is being asked to drive. Perhaps even with equipment racks and cables which may need time to settle. However, with a source component, I would think that there is less of this work required for it to function properly. We did give this five full days and spent much time adjusting things with the location and isolation of the controller, the arm/cartridge adjustments, etc. We worked pretty hard to optimize the sound over those five days, including phone calls to two people very familiar with the turntable, plinth, mat, Vibraplane, arm, and cartridge.
Finally, at the end of your post, you bring up particular traits specifically associated with turntable drive types. This one direct comparison surely does not answer the question for me about whether or not we can attribute particular sonic traits to turntable drive types, but it is a question that has always intrigued me. I just have not had enough experience with different turntable drive types in familiar systems to reach conclusions. Are you saying that in general, drive types have a sound? Spiritofmusic seems to believe this based on what I gleam from his writings about BB, idler/rim and DD. And it may certainly be the case with lower cost and poorly implemented designs, but I wonder if as budgets increase and restrictions are lifted, whether these kinds of sonic differences begin to be less noticeable. For instance, reading ddk's threads, it seems that the EMT and American Sound table sound more similar than either does to his TechDAS AF!, despite the fact that the latter two are both belt drive designs. Yet, with the exception of the EMT, he seems to prefer belt drive designs over all others. And then there is MikeL switching from a DD to BD table. I imagine that he hopes the AS will give him "more" of the good things he hears from his DD NVS rather than a "different" sound based on drive typology.
This thread has had some interesting posts, and I received a call the other night from a manufacturer who told me he once owned the two tables in this comparison and heard basically the same differences that I describe. So, it seems to me that there are varying opinions about the sound of these two tables, and as it has been suggested, this is all so dependent on system and room context, set up, listening biases and subjective preferences, that this is just one more data point around which we can focus to discuss ideas.
