The guesthouse is amazing. You share the backyard of the host's place, but they give you total privacy and detailed check in instructions. We never even saw the hosts for the whole trip, though they were always a quick message away in case we needed to contact them.
Healsville itself is a wonderful place. Lots of beautiful nature and wonderful wineries or restaurants to visit. You will have a lovely time visiting this place. Be sure to book during a time where there will be clear skies so you can see the night sky with minimal light pollution!