"How many Stillpoints and what locations have you found that work best Tom?"
My U-1PX's are on 4 Ultra 5's with threaded studs into where the spikes would normally be. With M-1PX's, I would do the same, but if you didn't want to spend as much, you could use Ultra SS instead, perhaps with the optional feet.
I would recommend using 4 under each speaker for stability, as well as the enhanced effect of 4 vs 3.
My U-1PX's are on 4 Ultra 5's with threaded studs into where the spikes would normally be. With M-1PX's, I would do the same, but if you didn't want to spend as much, you could use Ultra SS instead, perhaps with the optional feet.
I would recommend using 4 under each speaker for stability, as well as the enhanced effect of 4 vs 3.