I flew SIN to SFO on 1 Oct. This is a route that I often take, but this was the first time I was 'interviewed' by a private security agent. There were three of them standing a little podiums before you presented yourself and your bags at the check in. The questions only took a minute or so. It was basically the same as I often encounter departing AMS for the US. Then at the gate, where security screening takes place at SIN, there were more officers and more time taken to look at carry on and so forth.
But overall: typical Singaporean efficiency meant that there was really no additional burden or time requirement on the traveler.