I'm currently using ONA and it works great for me. I have a one quart jar of the gel/crystals and I have a one quart liquid to reconstitute it every couple of weeks. I crack the jar and the entire house smells fresh. You can no longer smell plant when you enter my house. It has been nose tested 3 times and all agree, no more plant smell.
I think if you are growing a skunk variety, or AK-47 or something along those lines, you will need a carbon scrubber. The ONA works fine with my grow, the strain is Bubblelicious.