I would consider the paint application on these minis to be somewhere between average and above average. While the quality of the paint application may not be great, many of these miniatures have a significant amount of paint steps applied to them. Because of this, I do think they are slightly above average.
The downside of taking photos with a macro lense, is that it will show off every little flaw on the mini -- it is sort of like placing the mini right in front of your eyeball. For general table top use, in which you would be sitting about 2-feet away from the minis, you will not notice these flaws and imperfections.
For mass-manufactured minis made at a fairly reasonable price, the paint application is going to have these types of imperfections -- the main challenge for the makers of pre-painted miniatures is to ensure the level of flaws and imperfections do not detract from the overall appearance or to decrease the amount of satisfaction one feels when using the miniatures. I think WizKids has met the goal of this challenge.
However, if anyone is comparing the minis in this set to WizKids' Pathfinder Battles minis, then you may note that the overall paint application of the D&D miniatures is not at the same level of quality.