You are on the right track- researching! Find out what you can, decide what you are most comfortable doing, and what you can afford... and go from there.
There are strong opinions on both sides of the organic/GMO fence on this forum, and in the interest of not arguing, I won't post my specific opinions here. I will only share my observations:
I feed an organic and soy free feed, and raised my chicks on it from day 1, so I never have had trouble with them being picky about what they eat out of it. This may not be the case for someone switching adult chickens onto it-- I don't know. There is a powder left that they don't eat very well, and so every few days I dump it out of their feeder and into a large bowl, mix it with a bit of water, and they eat it like crazy (it's gone within 30 minutes, so no risk of spoilage or mold).
I will also note that my coop, run, nor chickens have any odor to them. Fresh droppings can have a slight sharp odor if you are close by, but it quickly goes away and there is no lingering manure smell. I cannot tell you specifically why this is-- but I can tell you that I have had visitors exclaim their surprise at the lack of odor (compared to their chickens). And, having visited other people's chickens (that had clean coops!) I have to agree. I have to imagine that this must be dietary. Of course you shouldn't chose your feed based on 'how smelly it makes the chickens' but it was an unexpected (and welcomed) side effect for me.
My eggs have a slightly different flavor than those of a family friend who raises her hens on a different feed, but I will be the first to say that they are not better NOR worse in flavor-- just slightly different. The laying rate from my hens seems on average with anyone else. My chickens are not yet old enough for me to make any observations on long term health, and furthermore there are so many other factors that go into their health that any observation in health changes may or may not be linked to diet.
I hope this helps in some way!
