We installed the plastic tile floor in our detached shop/garage after the idiot drywall crew did all the mudding and sanding without covering up the concrete
and it looked like schit and wasn't going to come clean. Swisstrax
is the company. They were very helpful and nice to deal with. They have solid as well as "mesh" tiles. Note that the solid tiles aren't sealed when locked together. Moisture can still get through the seams, but not in any great amount.
I will say that they are easy to install and very durable. I've found them very difficult to scratch or dent. The only thing they have no resistance for is heat, i.e. don't put them down in a weld/fab area. Weld spatter and/or hot metal parts from cutoff wheel use will quickly melt into the surface....
don't ask.....but at least if you wreck a tile (or several) they are easy to replace.
Cost-wise, I priced the plastic tiles against industrial-grade epoxy floor coating and it's about a wash. They are both expensive. However, in my experience, anything less than industrial grade epoxy coatings will not last. The DIY Rustoleum stuff is junk. Looks great for a year or two, then it all peels off. Industrial epoxy coating requires that the surface be ground down (Dan, I had no idea you could rent those machines!) and a thick primer/leveling coat and then a finish coat. The finish coat should have some sort of grit spread across it for slip resistance otherwise it will be spectacularly slippery when wet.
The only other downfall of having a nice looking floor is that it will show every speck of dirt, mud, and dust. I vacuum AND MOP the shop floor regularly.
Here is the floor shortly after completion:
Here is the same view but I've got a boiler parked there now: