shame.
yeah. we've never used our AC for heating
our units are in the loft space. they are large though so you do need space! servicing them the guys just go up to the loft and work there. we did visit a house where they had them in the ceiling so had to have a large access panel which aesthetically might not please some. we have one unit attached to the joists so is silent as anything. the other above our WIW (which is open to our bedroom) was sat on the joists and vibrated a bit so i got them to sit the unit on some rubber which has reduced the vibrations to barely audible.
honestly, barely audible. we have it on 24/7 in the summer and i've never once thought about any noise from it.
not used it for heat so can't comment on that sorry.