Don't buy anything which is on reclaimed land, slope. Reclaimed land is not stable, especially if they dump rubbish. One thing to keep in mind recently -

earthquakes. Reclaimed land in penang is not as stable as you think - earthquakes makes it even worse. Now the volcano belt in indonesia is going active again, you might not want to invest there if you do not want cracks appear in your walls.

This ofcourse depends on how they reclaim it. 5th Street and 7th Street (forgot the name of the area) was a reclaimed land for over 30 years. It actually sunk and recent earthquakes made the situation even worse. I dont have source about this, I think you should ask and research about land reclaimation houses before you buy one.