We used it for three years on a Turbo Beaver and never had a single squawk with the Chelton system. It offered a lot of features for an aircraft flown IFR -- airways, TAWS, WAAS approaches, and visual approaches with a glide path.
For a VFR helicopter, flown by looking out the window and keeping two hands on the controls, it seems like a lot of button pushing compared to having an attitude indicator and a Garmin 396 or 496 paired with a 430 or 530. The bugs panel (dedicated buttons for setting heading, altitude and course without pushing multiple soft keys on the displays) has been "three months off" for the last three years. The wind vector on the Chelton is a great feature.
George