I am just finishing my first 1 gallon kit.  Here are my comments/observations:

The epoxy is very viscous and the hardner is very "thin".  It makes mixing a bit more of a challenge.  It also seems to introduce bubbles into the mixture, no matter how careful.

Non-EZ colorants seem to be slightly incompatible.  They seem to have the oil/water effect resulting in odd streaks and inconsistent colors.

The mix seems to be very sensitive to exact ratios.  Originally I used the supplied pumps and had mixed results...some soft sets, some hard/cracked.  Towards the end of the bottles, I started measuring out exactly 3:1 using a table spoon and have had much better results.

Overall, for the price it is a decent option.  If you want perfect, you may need to try the EZ pulg colors...  Not sure about minimizing the bubbles though....  I will probably buy another kit for my own personal use.

S^2

I've also bought this product and found it to be good as well. I did notice that the color acted like the oil/water mix, but it colored well. I haven't had any bubble problems, but I always do the slow figure 8 mixing of all ball plug. I haven't had any slow plugs or cracks, but the pumps aren't as good. I always push slowly as recommended and I have to prime the pump almost every time. I just push slowly without letting any material out to fill the pump. I did notice the pumps drip slightly and the others do not. Just my $.02, Bruce