sorry to revive an old thread, but i feel that i need to share my point, so others would be informed.
For those who think that the top floor unit has more cons than pros, that's a misconception. I have lived in low (4th) floor for 20 over years and my parents have once told me that high floors are good but top floor is not, because of the following possible factors:
1) too hot because of direct sun shine
2) leakage on the roof
I have a friend who also stayed on the top floor for 20 over years, and i went to his house many times. This is what i can deduce from his and my experience:
1) it may be hotter but heat also dissipate faster. When weather is cold, it's colder. in fact, i think the, in Singapore, the keypoint is whether the unit is facing which directions. The units are much hotter if it has a West shine. It would be the worst like my parents' unit, which we have both West and East shine. Meaning half windows are facing West, another half facing East, none to the others.
2) as some pple here have said, leakage/cracks chance on every levels' ceilings. Think my friend house got a crack and used to leak on heavy rain, but HDB did something to it and never leak again. I believe nowadays, new flats have less occurrence of cracks.
3) no noise from neighbours above is a very very important point. You wouldn't find it important until you really experience slamming doors, dragging furnitures, stamping feet from your neighbours above you.
Hence, i have chosen a North facing (East tilt) unit at the top floor from HDB BTO.