When you find one you like then stick with that brand for all the others you buy. The only exception I suggest is when there is a very special ruler for a special project such as wedge ruler. All rulers are not created equal and the lines on one might be slightly different than the other. I prefer the Omnigrid because that is the brand i "grew up in quilting with" so have the 6"x24" 6"x12" 12.5x12.5 and the 6.5x6.5 etc etc. Then purchase speciality as they ae needed for a project. An example of this is the "Strip Tube Ruler" for the strip quilts.