Yes, I do.
Benefits....helps circulate water so their are less dead spots in the tank,
if the power head is near the surface...it causes ripples in the water and helps oxygen levels,
if you fish are big swimmers they will like to swim against the current in the tank,
if you use live plants they sway in the current if you position it right.
can be an eye sore in the tank,
if your fish don't like heavy current they wont swim where their is a current.
If this is for your 55gal i say yes. It looks like you only have one filter (Emperor 400, im guessing) on the right side of your tank. I have a 60gal with close to the same dementions with and emperor and it used to have dead flow spots before i added another filter.