I lean towards PBL cleansing polish.
To observe it's cleaning power, try using a cutting (like orange) pad on glass, you'll observe how much dirty and grime it removes in few passes, also ~90% of waterspots cases (but not in the worst baddest cases (the last 10% or less).
This using speed 5 on Flex 3401, some pressure, and 3 to 4 passes with slow (normal) arm movement.
It always wonders me on windshield while I'm prepping for a coating.
It's just not the easiest product to wipe off. No, it's not dry to the paint stuff, it's very concentrated so you will have to wipe it turning towel side often to remove everything without letting residue left.
I was able to polish entire car with it then remove everything at the end with no issue at all (just the normal work of wiping polish off an entire car at once ahhahah).
I like this product.
Cons: Expensive
Fav: Lots of AG seasonal discounts and coupons!
I've used PBL cleansing polish on a coated car to clean and rejuvenate the coating, worked as expected. I've used a finishing pad (no cutting) to work this out, since I would not want to cut even the finest polishing pad over the coating.
When prepping for coating / sealant / wax, I will use it with a polishing pad, at least (generally white CCS, flat, hybrid, etc).
However, if you are not leaning toward coating, maybe the cost would be excessive for just a prepare for wax product.
Hope that helps you in any form.
Kind Regards.