I've also been considering different types of soil. This is my first grow. One of the plants is in MG, and the other two are in some cheap stuff I found on clearance. All three plants were very healthy throughout veg, and I'm certain that any fertilizer from the bagged soil is long gone. Now the plants are in flower, and they get a high-quality high-phosphorus organic fertilizer. I don't think you should have issues with any bagged soil as long as you are careful about what nutrients you add to that soil. I'm actually considering picking up a soil/sand/compost mix at the local nursery for $40 a cubic yard in order to save on the cost of soil, but I'm a little concerned about what uninvited guests might arrive in that soil mix.