[mzo]

I found that when playing indoor (e.g. Ultimate Airsoft) that when I entered '"maze" like areas it was much easier for me to maneuver and acquire my target using a pistol compared to my MP5 (before I had my MP7).
However if you are using an MP7 you will most likely not need a pistol to better maneuver tight spaces, though it would be nice to have a back up in case your primary goes down or you run out of ammo for your primary.