As a constant gardener indoors, I can go through a dozen 2 cu. ft. bags of soil a year, easy. I've tried most of the main garden retailers soils (Lowe's, from local nurseries, etc.) and found them to be very lacking.
Anytime they stack soil bags outdoors, quite often I find they are rain soaked, and worthless. They use bags with small holes to vent gasses, but it also
allows fungus gnats to lay their eggs in the damp soil.
Now, I strictly use Fox Farms Ocean Forest or Happy Frog, and then
add about 30% more perlite. Drains well, but still holds plenty of
moisture.
Bill, have you ever used compost tea? Great stuff! I also use "Recharge" from Real Growers, a microbial powder that does wonders for root structure,
and nutrient uptake.