Do it. It was a weekend worth of work, but I would do it again in a heart beat. It hasn't been down long enough for me to be able to say anything about its durability, but it looks fantastic.
I used the Rustolium EpoxyShield you can get at Lowe's or Home Depot. The prep work is the biggest part. Most garage floors have a sealant of some type that you have to get off. The Epoxy Shield kit comes with an acid wash that etches the concrete surface so the epoxy can bond to it.
Friday night I pressure washed the garage floor, used de-greaser and a scrub brush on oil stains, rinsed the floor, acid washed and brushed the floor with a stiff bristle brush, then pressure washed the floor again. Saturday morning, there was a residue on the floor from the acid wash, so I pressure washed it again, let it dry all day and all night. Sunday morning I rolled on the epoxy coating. The epoxy sets up quicker in hot temperatures, so being in Houston in June, I had to apply the material early in the morning so it wouldn't set up while in the bucket.
I am planning on putting a fresh coat of light grey pain on the walls to clean them up this weekend, then the garage storage and organization begins. I have an original saw 'em off flag (pre skull patch,) a come and take it flag, a Block ATM with the state outline, and 4'x10' Beretta banner to hang on the walls for decoration.