The most pro method is to use the hardware vsync rate. If you don't sync your flip to the hardware rate, you'l have cut off frames. Since the hardware sync rate may be diffrent depending on the settings, you need to use delta timing to make sure the game is running at the same speed on all machines.
Personally I offer an alternative Flip mode in the game Menu. (VWait:Flip 0 vs. Flip 1, but both are using delta timing)
Personally I offer an alternative Flip mode in the game Menu. (VWait:Flip 0 vs. Flip 1, but both are using delta timing)