Thanks Munta,
Back on topic.....
I have researched around 200 properties in the area ( townhouses, units and houses) and I feel it boils down to 4 points (please tell me if you feel there are more)
1. Architecture
2. Location ( views, beach, shops, etc.)
3. Age of property
4. Living space (bedrooms, living space, land size)
I believe solar orientation has/ is becoming important, but on older property I don't think it has a dramatic effect.
Personally, when it comes to the crunch I would prefer one less bedroom (3 instead of 4) and less cramped living area than 4 boxy bedrooms. Even with 3 bedrooms if bedroom sizes are a bit larger, siblings could possible share a room.