You need to (sometimes) control the throttle manually, or know how to tune your 1st gear according to drivetrain, power, weight distribution, tyre composition, ect.
In a rolling start, the only way to have an advantage is to have the rolling speed match the RPM that Peak power is produced (Eg. 550hp @ 6000RPM)
My preference is bias as it depends on the car I'm driving. If I'm in a 4wd/AWD vehicle I love the standing starts. If I'm in something without 4/AWD I prefer the rolling start.
I have to say, I was less than impressed when PD removed the standing starts from most of the single-player. At least the standingrolling starts work properly now, though, in that everyone goes as soon as first place crosses the line, not like in GT5 where you'd individually wait until the start-finish line!
It was such a great feeling to be able to do standing starts online in that game. It makes all the difference; it really makes the start worth something and it doesn't put you in hot-lap mode but "battle" mode, which is as it should be. Unless you're a rammer.
I only really have problems with FF cars in GT5 on a standing start, but I'm not sure that's entirely my fault