Oh, with a revolver, you always can choose between single and double action with each shot if a double action pistol, as it does not have a gas operated mechanism.
Except for single-action only revolvers, of the Old West type. ;-)
It largely comes down to personal preference.
The first double action shot will almost always be somewhat errant due to the longer and 'heavier' trigger pull. After that, they operate the same, except double-action only (DAO) pistols.
In a real stress fire situation, the average person wouldn't want to bother with something like racking the slide after drawing the pistol. This presumes your off-hand is free to rack the slide, which may not be the case for a number of reasons. Its one more step that can up the degree of complexity in a situation where simplicity/speed wins (and losing means something more serious than wounded pride).
The Israeli military does teach this method, but they also drill it a thousand times - off hand and single hand. So if you are willing to invest a hundred hours in this one technique and know a skilled single-action instructor, then by all means. Most people, however, will not.
Single-action pistols like the venerable 1911 .45 demand a higher degree of discipline and proficiency because carrying Condition One or 'Cocked and Locked' is far less forgiving of imperfect technique and the slightest deficiency in trigger discipline. However, it is considered the optimal condition of combat readiness in a service arm.