Duratex is a very good DIY coating, and a lot of us who build small production or custom cabinets use it as well. It is not as durable as the Line-X, Speedliner, or similar product, but it is much more durable than the lacquer-based Texturlac. Since it is water-based, there are no dangerous fumes, and clean-up is very environmentally friendly.
We have been applying it over a base coat of satin black latex, and it does quite well. If you want a very consistent finish, try the rollers that they offer. We are using a Graco RTX 650 sprayer, but I'm not quite gotten the technique down to my satisfaction yet. The hopper-gun systems won't work for us, as I need to spray inside as well as outside, and the occasional "splats" and clogged tips are just too inconvenient.
If you let it cure for 5-7 days, it is quite effective and durable.