My favourite QD spray is Clearkote Quikshine. Not cheap but I find it leaves a wetter finish than any of the Megs QD range.
I'm also on my 3rd bottle of Red Mist. I've gone for the tropical version this time as I found the 'normal' version solvents flashed off a bit quick in the hot summer sunshine.
Red mist gives me 3 weeks visible durability on my daily driver even in winter conditions. I find Red Mist leaves a deeper wetter finish that the Zaino equivelent Z8.
As previously said, it's important not to confuse spray sealants like Red Mist with QD's. If you try to use Red mist on anything other than a perfectly clean and dry surface you will probably end up with a smeary mess - plus seal in any dust / dirt into your paint. Used properly, it can really add a 'something' to even a recently waxed car, although I tend to use it to extend the life of my LSP after say 2-3 months when I should possibly be considering stripping, prepping and reapplying fresh wax.
I have used a QD to remove dust on my cars but only very light garage dust - the thin dust I might find say 3 days after washing a car and garaging it without use. Definitely wouldn't use QD to remove anything heavier for the risk of marring the paint.
I usually just use QD
after drying the car to leave a nice slick finish.