Sort of depends on what buffer you are using and also just personal preference and experience with different paints combined. Extra cut pads i only use with my porter cable random orbital, they are excellent at getting out bad defects and sanding scratches. however, you can not just use an extra cut pad and then wax because you will see very fine scratches in the paint (not scratched like from a rotary aka swirls) its almost a haze. This haze is a result of cutting out the bad defects but can easily be taken out using a must lighter cut polish like M205 or D302 with either a regular cut pad or finishing pad depending on the softness of the paint. The reason i dont use extra cut pads on my rupes DA is because you need some backing on the pad and the rupes has more cutting power. I use regular cut pads on the rupes and can pretty much fix anything. I also use M205 with the cut pad on the rupes on most cars, but if i see any haze i switch to the finishing pad. When applying wax/sealant i only use the finishing pads and my porter cable. I really like M85, its old but works well for me. I like it because it cuts as much as M105 for the first pass or 2 and then starts to diminish in to a polish more like M205, this makes it almost a true 1 step polish if you know how to use it correctly and properly understand whats happening. either way if you go over any car you polish with a finishing pad and D302 i think you will be happy you took the time, it really makes the gloss crazy!
