OK, here are a few photos for you...
The floor is Rust-Oleum's "professional" mineral-base epoxy coating. By all accounts, a "cheap" epoxy floor. It's around ten years old +-. Preparation consisted of etching with muriatic acid followed by applying two coats at the recommended re-coat interval with a 1/2" nap roller.
First, a few "clean" photos from late 2011, a month or two after I scrubbed the floor:
Now for some "dirty" photos. I usually scrub the floor with the floor scrubber as part of spring cleaning. I sweep every day and mop once a week. These photos are before mopping at the end of this week. To show what the floor looks like after scrubbing, I scrubbed test patches with the corner of a green scrubbing pad using Super Clean.
First, the "dreaded welding spatter" that everybody is afraid of. This is in front of my welding table. I take no precautions to protect the floor. The majority of it comes up with a few strokes of scrubbing. The floor scrubber will take it all up:
Next, the general shop floor and some paint overspray. The pock marks you see in the floor are mostly from drops falling off my horizontal band saw. When I remember, I usually place a 30" square piece of 3/8" plywood under the saw to cushion large drops. In most cases the epoxy doesn't chip unless the underlying concrete breaks.
Finally, in front of my lathe, the only part of the floor which has begun to wear through due to grinding chips into the floor. I usually stand in one spot and it shows:
A photo of what causes the damage and what it looks like after scrubbing: