Having read up on the Q factor I’m still not too sure if it will make any difference to my riding or if indeed I need it. All my pedals are fitted without washers. Do I need washers? Is it a good idea or not?
Imagine if your pedals were each 50mm further out. That would matter. I know it's an extreme example, but only to make a point. If your saddle is too high or too low by 5mm, you could tell. Q factor is similar, (In my opinion).
Ref the washers. The washers are only there to stop the steel pedal axle biting into the alloy crank. This is especially useful if the pedals never get removed from one year to the next!