I found some interesting information on the web and thought I would post them for everybody to look at. It helped me to understand some differences in different sanding media
Scotchbrite Grit Chart
7445 - White pad, called Light Duty Cleansing - (1000) 1200-1500 grit
7448 - Light Grey, called Ultra Fine Hand - (600-800) 800 grit.
6448 - Green (?), called Light Duty Hand Pad - (600) 600 grit
7447 - Maroon pad, called General Purpose Hand - (320-400) 320 grit
6444 - Brown pad, called Extra Duty Hand - (280-320) 240 grit
7446 - Dark Grey pad, called Blending Pad (180-220) 150 grit
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150)
Blue Scotch-Brite is considered to be about 1000 grit.
(The value inside the parentheses is directly from Scotchbrite)
Comment: #1 ----- There are some main differences between sandpaper and abralon. With abralon, it uses silicon carbide particles that are precision sifted to a consistent grain size. So you know for sure what you are using. With sand paper you will have imperfections in the "grit" and wears out very quickly so 320 can become 600 very quickly.
Also water/oil lubricates the sanding process well but flows thru the pads whereas, sandpaper will cake up. Therefore, again sandpaper will not give you the true grit you are looking for.
Comment #2--------as far as I thought, Abralon, scotchbrite, sandpaper etc, are all just abrasive media used for sanding/cleaning. The grit measurement system originally came from sandpaper, and then got used for polishes, and not they use the term for abralon/scotchbrite pads to give a reference to what relative "grit" it will sand to, in other words, for example, "a green scotchbrite pad gives you the equivalent finish of 600 grit wet 'n' dry sandpaper". So, really there isn't much difference between each, I would assume though that there may be some difference in finish between abralon/scotchbrite vs. sandpaper, but if you use the equivalent pad/paper, the difference would be insignificant at best.
Comment #3--------Typical wet/dry sandpaper also uses silicon carbide, same abrasive as abralon pads. I'm not sure I see how sandpaper will wear down faster than the abralon if they are both the same material. With the sandpaper, you will want to make sure you rinse it good to get the resin off the surface as the water does not flow through the sandpaper like it does with the pad.