I am looking into buying my first set of Hedge Trimmers. I have it narrowed down to brand. Shindaiwa. Its all I use except for a Maruyama line trimmer I use. My question is this: what are the pro and cons and more importantly the DIFFERENCE and advantages of using a Single sided trimmer as opposed to the Double sided. They seem to be relatively the same as far as pricing goes. SO why would one want to purchase one with only one side? Can you explain this ti me to help me better understand?