i've been paper piecing for years---and didn't have one for years---and was successful- but i have to say- when i finally did get one i really wondered why i waited so long- i love it and use it all the time now- it makes it so much easier- faster-
and a regular ruler with a 1/4" mark does not take the place of it- the ruler has a (ledge) that you line up with the edge of the paper- then you cut giving you an exact 1/4" line to line up with for your next piece- it has really made my paper piecing more fun.