I use my 6 X 24" and my 12 1/2" all the time as I cut a lot of strips and almost slways make 12 1/2" blocks and need to square them up. I also use my 8 1/2" ruler frequently both to cut blocks and square up smaller blocks. Many of the scrap quilts that I make start out with 4 1/2" strips or 8 1/2" strips. I also have an 8 1/2" X 24" ruler which I use quite often but as it is much wider, it is heavier to handle. I put the rotary cutter shield on this one so it wouldn't slip when I was cutting and cause a nasty accident. Having the right rulers available just makes quilting easier and safer. I think they are a good investment and haven't worried about having different sizes. I also like my 3 1/2", 4 1/2". 6 1/2" and 9 1/2" squares which I use to square up blocks and parts of blocks. I know I could do this using less rulers but I like the convenience of just grabbing the right size and trimming up without having to fiddle to get the right size.