You might laugh at this, but I like making you laugh, so: I'm afraid to break the disc spindle, so I don't use it. It's on show in my spindle rack.
I would like it if you would make a few copies of "the Spindle from Hell", since I would love to play around with it, now that I know a lot more about spinning. Besides, I often talk about what we did at the Forums and it would be great to have that spindle since it was made to be weird/lousy on purpose. I would buy one right away!!
I've bought one of your spindle whorls (along with three sticks). I've not used it extensively, however it was far more robust than I anticipated. It tends to stay on the stick very well but has slid off a few times. It slid off onto stone paving at least once and although a chip has come off the top side, it's still perfectly fine in terms of weighting, balance, structural integrity, etc.