Never used Vallejo primer, but I love their paints. The VMC and VGC lines are great and I have heard good things about Vallejo Air. What is wrong with the primer? Does it not adhere well to the material? Is it too coarse?
The thing I do not like is that they are primed with the molding lines still on. I hate mold lines on my models with a burning passion, and the difficulty of removing them on Bones models is what turned me off to that material.