It is a detergent...
If you read their site, you'll see why they call it "Soap" even though it's really a detergent. I am a convert. It's the best stuff I've ever used. The problem is, it DOES take time to realize their claim of not having to use fabric softner. Things have to be washed multiple times before you'll begin to realize the softness. You'll probably have to go through 1 80-wash load bag first. But...I stuck with it...and it's true. The stuff really works. For things that have never been washed, they retain the softness they have when new (and sometimes, depending on the fabric and how it has been treated, are actually softer than when new). For things that have been previously washed in other detergents, they'll need a few washings to get back to their original softness.
I absolutely hate the fragrances in detergents. Even the Tide Free I was using has a scent now. That's why I was trying to find something that was truly scent free. The Charlie's fit the bill perfectly. And...I haven't had any stain it could not get out.
It's certainly not a "miracle" detergent like some of that "cult-like" following you were alluding to claims (as in one wash and everything is miraculously soft)...but it is, in my opinion, better than Persil or other high-end detergents I have used. You just have to give it time for the full results. Once you see what it can do, you'll be hooked.