This is from my personal experience, YMMV.
I had my garage epoxied when I bought it. It's one of the biggest mistakes I made with regard to home improvement.
If you do any sort of work in your garage, I would advise against it. My floor is beat to hell, with the random tool drops, jackstand holes, etc.
I'm assuming you have a truck, and if you park it inside, the heat from those big tires will soak into the floor, and it will end up peeling off so you have 4 nice big spots in your floor. And they will end up getting bigger and bigger and bigger
Tax return time I intend to redo my floor, but this time with Racedeck or something similar, or vinyl composite like someone else mentioned above.
My garage gets a ton of use. Working on cars, my landscaping equipment, woodworking projects, etc.
I will say that I prepped the hell out of mine, going above and beyond the instructions. I've had a floor fail in the past due to improper prep work so I know the importance of the prep. I know that my slab has a vapor barrier under it (I had the house built) so I don't have moisture problems from underneath.
When I prepped mine here were my steps (taken from a previous thread of mine)
-I got started on friday night, took everything out of the garage (workbench, compressor, table saw, lawn equipment, etc. Put it all in my kitchen lol.
-I pressure washed it out with a little 1800 PSI karcher unit. I did this about 3 times on friday night. I also scraped anything off the floor (wood puddy, paint, glue, etc) with a shovel and/or a razor blade.
-Saturday morning I pressure washed it again.
-Then scrubbed it with a purple power degreaser solution. After that I rinsed it out a few times.
-Mixed up about 1/2 quart of Muriatic acid in about 2.5 gallons of water. Always wear eye protection, gloves, and a respirator bc this stuff is corrosive and can burn your skin if you have sensitive skin. I slowly poured this on the floor working in sections using the squegee to evenly distribute it and using the deck brush to scrub it in. When you hear it fizzing you know it's a strong enough mixture.
-sprinkled baking soda all over the floor to nuetralize the acid, then rinsed this out about 3 times to be sure I got all of the acid out.
-I cleaned the floor again with a purple power solution and rinsed about 2 more times.
-Now I used the etcher/cleaner solution that came with the kit. Followed the directions and mixed it in 2 gallons of water. I applied this just like I did with the muriatic acid.
-I rinsed it out about 3 more times with the pressure washer.
-Squegeed the garage dry.
-Then I set up 4 box fans in the garage. I pointed one fan from one corner facing the other corner, The next fan then points towards the next, and so on. Basically this created a clockwise vortex of airflow to dry it out. I did this at about 12:30PM and left the fans on the rest of the day (with the garage door open while I was home) and they stayed on until I painted the next day (about noon on Sunday) so I basically let the floor dry for a good 24 hours.
-Sunday morning about 11:30 I mixed up the paint, following directions, based on temperature you have to let it sit for a certain amount of time after mixing before you start painting. (make sure you wear gloves and a respirator, longs sleeves aren't a bad idea either, I had to use rubbing alcohol to clean the paint off of my elbows and knees)
-Cut it around all the edges and the small vertical sections of concrete with a paintbrush (buy a cheap throwaway brush)
-Then I began rolling the floor using a 9" roller with 1/2" nap. I would paint about a 3'X6' section, sprinkle the flakes/chips, then move to the next section.
Painting the floor took less than an hour but prep work took about 4 hours minus drying time.
Let the floor dry for 24 hours before you attempt to walk on it or put anything back in the garage. The kit says wait 3 days before pulling the cars back in the garage. I say 4-5 to be safe, and use cardboard under the tires for the first week.