My 49th lifetime Ton-80 came off what was billed as "the world's smartest darts". I never had any business dealings with the guy who made and marketed these darts, but whoever it was included a few very interesting things into his dart design.
The points are spring loaded, and a fairly standard spring loading at that, however, the design of the nose is kind of nice. These were made in the era of ugly conversion points so these, at the time, were a breath of fresh air. The springiness of the points is a bit on the soft side though. I happened to get this set on ebay so I did not get the case or the original stems or flights. While the stems themselves were a standard in-between length nylon stem, the flights were a unique size and shape which I found highly, highly appealing. They were almost the same shape as a standard flight but probably 10 to 20% smaller. I wish I'd bough 100 of them when they were available.