The bus tour starts at SunTec City mall , which is where I would recommend boarding the tour due to high volume of passengers. There are two routes: red and yellow. The red route goes to more older traditional locations whilst the yellow goes round newer locations . Overall we preferred the red route.
The commentary is by pre recorded headphones and is quite informative. The buses travel at a reasonable speed allowing you to view the sites easily.
We booked the tickets online under big bus Singapore, and suddenly I received an email from a company called Headout and an SMS from a USA number ( also mentioning Headout). I was sceptical that I had been scammed but the tickets were within the mail and when we presented the tickets at the boarding point all was ok. So it does work ok.
The red tour was very enjoyable but, for me, the journey through little India was the most memorable part due to the wonderful array of spice smells!
We never got off the bus as stops were busy (it was Chinese new year time) and enjoyed seeing the sites.