I sell several of each of these machines each week. I love my bias tape maker machine by simplicity. I make lots of things with straps so it comes in handy.
The rotary cutting machine by simplicity is great if you cut a lot of strips. It is perfect for making rugs, making jelly rolls and locker hooking. There is a tip sheet I send out with it. It cuts with a pressure cut and not a razor cut. You adjust the pressure with a screwdriver.
I have posted photos of me using both on my blog. Stop by and check them out. www.IHaveANotion.blogspot.com
Hopefully you'll be able to make a decision if either of these tools are right for you.
My website is www.IHaveA-Notion.com stop by anytime.
Smiles,
Kelly