Quick detailing is essentially a waterless wash process. A spray of cleaner is liberally applied to the bodywork then this is wiped down with a microfiber towel. As you will hopefully have identified this is a ‘high risk’ method of cleaning a car as there is no rinse process and no deep woolen pile mitt used to remove dirt!
I will never suggest using a waterless wash technique as a means to clean a genuinely dirty car as there is just too much scope for dirt to clog the microfiber then mar the surface of the paint inducing the scratches we are trying to avoid and/or correct.
Where quick detailing does have a use is in top-up cleaning. If I fully clean the car this will take about an hour and at the end of this I am ready for a sit down inside! If I decide I want to polish the car or similar either later that day or perhaps the next I will quick detail the recently cleaned paint (assuming the car hasn’t moved) then begin polishing.
Why is this safe? Because I have already removed all the major risks by performing a full wash. Quick detailing will remove any dust and light fall out ahead of polishing.
As a cleaning tool quick detail spray is very versatile. Per above I use it if I am leaving the car before polishing/waxing but I will also use it to clean the car after it has been clayed, if I notice a random spot of dirt. Further most clays require quick detail as lubricant and it is useful when polishing to lubricate pads and remove stubborn bits of polish so it is useful to have around.
I use Meguiars quick detail which is excellent at what it does, however I try and avoid this technique where possible due to the risky nature of it.