Quikrete garage floor coating is a good product and does what it claims to do. To echo just about every other reviewer, one MUST take the time to prep the concrete prior to application. Also, be sure to mix parts "A" and "B" thoroughly and let sit, covered, for thirty (30) minutes prior to application. If you follow the directions and use some common sense, your floor will turn out well. I don't believe some of the horror stories I've read on line. The only way this product will flake off immediately or not cure properly is if you do not mix it thoroughly and/or do not let it sit prior to application.
If you've taken the time to prep your concrete and apply the color coat, you should apply a clear top coat to seal in the fleks and add depth and durability to your floor. Then, once the floor has cured, apply a few coats of wax. I use my garage as a combination workshop and library. I do not park our cars in it and have no caustic chemicals to spill on it. The weather here in the San Francisco Bay Area rarely dips below freezing, and my floor is not exposed to direct sunlight. So, it should hold up well. If you are looking for an ultra tough floor with showroom depth, then you're going to have to pay quite a bit more for it. If you have that type of floor done professionally, you're looking at $3,000 easy. It all depends on your needs and what you are willing to spend.