Quinoa is higher in protein than most grains, so subbing it in is a good idea if you are looking for that; I believe that's why most say it's healthy. I'm not sure where it falls in comparison of carbs and glycemic index, though (Pam?? You would know this!) It does tend to be more of a calorie bomb than, say rice or pasta, though, per volume.
I've not tried it cold in salad, but I use it mostly in a lovely recipe with shrimp, green onion, toasted pine nuts, raisins, and some spices. Will try to find the link or type out the recipe later if you want...
And now that you don't have to be perfect, you can be good.