I bought them a few months ago along with a couple different wheels when they were the sale item of the month (20% off the holder and wheel sets), but haven't had a chance to use them yet.
As with most Sherline tooling they are well made and designed to work with the very small size of the Sherline lathes. I don't have experience with the cheap scissors type, but they are a lot cheaper than good quality scissor types like the Eagle Rock ones that many have recommended.
Longer term I have Mikey's knurling tool on the to do list, but that is a long list and time to play with my machines doesn't seem to be happening as much as I had hoped.