I had the garage floor epoxy coated when we finished building the house last year. I did it more for aesthetic reasons rather than anything else but I was amazed how at much dust this prevented. This is the 4th house we've had since moving to Aus and all previous garage floors have just been standard concrete. They've always been really dusty but I just assumed it was dust blowing in when the door was open, or past the doors as the doors aren't sealed around the sides. Clearly I was wrong and most if it must have been coming off the concrete floor as the amount of dust we now get is minimal.
Other positives are that it looks great, is much more hard wearing than the concrete, and easier to clean. No marks, dings and dents when you drop things. No stains.
About the only down side (other than having to pay for it) is that it can be a little slippery when wet, and water can not soak into it. This means that in the winter when the temps are low and water doesn't evaporate too quickly, it can stay wet for a few days after a wet car has dripped on it. Not an issue in the summer as it evaporates off really quickly.
I used a company called E-Coat who are based up the central coast if memory serves. No affiliation, but they did a great job.
