I now have had the MK1 Brass Performance for 6 months. Together with the famous Lambda top, it's one of my best two. With any of them, I reach 10 min spins on a cheap 3x mirror (but I've seen videos of 15 min). And they spin in a very smooth way, with no wobbling.
As soon as I received the email announcing this new campaign, I joined for the copper version.