Of the ones listed, I've used only the paint sealant (10QT). Very fast drying. As long as you apply it thin and in the shade, no problems removing. If you have "ridges" as you apply, you're going to be in for a hard time removing them. Looks nice and reflective. Pretty good depth, I think. I can't comment on durability, other than it lasts over a month. Also seems to be able to remove light oxidation.
I like the XP Polish. Works pretty quickly on cob webbing. Doesn't haze the paint. I don't recommend letting it dry before removal (directions suggest it). I find it comes off easier if you remove it right after you are done working it.
White Magic is a pretty good 1 step wax. Blends in light cob webbing. Nice shine. Pretty good durability for a wax. Dries fast, so you can do section by section or whole car at a time.
Their blue glass cleaner concentrate is a pretty good value. 3 oz. per gallon of water. Smells of alcohol. I'm not sure if this is VOC compliant or not. Works well, though. Cuts through films pretty easily. Can streak, though. The streaking seems to be dependent upon my towel. No streaks with the PB velvet MF.
Seal It (not the XP) is very liquid. I found out after my first use of it that it can/should be sprayed on. Nice reflective look without looking too bright. Again, can't say if it lasts longer than a month.
GS-1 is a nice "final polish" when working on dark colors. Adds a little something extra.
EZ Clean (Upholstery/carpet cleaner) didn't impress me. But I have heard others say they like it. Maybe my technique was "wrong."
These are just my "initial" thoughts. I don't use these products too much, as I have lots of others to keep trying out, but I would imagine that a competent detailer should be able to turn out good work using these products.