Hairyplane
Have flown R44 with all conbinations of doors on and off, have not had any bad effects, most of the time the noise you here is seatbelts flapping. Make sure there is nothing to fly out in airstream. Other down side is need for PTT use for talking as wind over normal mic setting sets them off.
BVGS
There are a few Astro's around that have hydraulics like the Raven from the factory. Frank put on the hyd. then when they worked ok decided on the new name.