Actually, QDs are in three, different catagories: cleaning, during and after wash touch up, and enhancer/topper. For cleaning there is only one to consider as it gets no better than Poorboys Spray and Wipe. It takes nothing from the finish and returns nothing, ie, it adds some extra shine but not much. A concentrated version of DP 4 in 1 is also a good, cleaning only QD. Lately, I've been experimenting with Duragloss Fast Clean and Shine and it cleans almost as well as the SW but adds a bit more gloss. This one has potential! But in this respect, I think I will put it in category two, as I would the FK425 that others have already mentioned. Eagle One and a few other otc brands are also good products that do well as a general, all around QD but as in any compromise, peak performance is achieved at neither end. These kinds of QDs add gloss and a tad of additional, short term protection to your last step product, be it carnuba or sealant. And they'll clean up bird bombs, dust and finger prints okay but can't compare to the power of the Poorboy. Dollar for dollar they are hard to beat.
The third kind of product should not really be considered QDs at all but they are often mentioned in detailing circles (and even advertised by their manufacturers) as such. These are usually polymer/acrylic toppers rather than wax based. Products such as Menzerna High Gloss Acrylic Shield, Wofgang Spritz, Sonus Spritz and several others seem to have part sealant/glaze in their formula based on their related entity. For example, the Menzerna has some of its sealant (Full Metal Jacket) in the HGAS formula. So too the Sonus is directly related to Klasse Sealant Glaze. Werkstats Acrylic Gloss is virtually a diluted version of their sealant, JETT. Duragloss Aquawax (which contains no wax but rather polymers) is used as a QD over the Duragloss 111 or 105 last step products. These specific products do not clean very well but they have extra boosters for added gloss and they enhance the durability of the specific sealant they are related to.
The bottom line is you should be aware of the attributes of the various products out there and be sure you get what you need for your purpose.