Depends on how accurate you want to get or how consistant you can duplicate your form. You can take a .006 arrow and shoot great with it, but I wouldn't go mixing arrow brands, spine, weight, etc. I will always shoot a matched set of arrows right down to their straightness. When I make a bad shot I want to know it was all on me. I don't want some excuse in the back of my mind saying...that error was caused by the arrow, etc. This is my opinion because I like to refine whatever I'm working with. Keeps me busy and when I make a mistake I know it right away. It's your choice and your level of peace of mind.