The reason I like it is pretty straightforward... and I should say that I'm no more married to it than Promix BX or Sunshine #4. As far as I'm concerned the triple mix I get in bulk from my local peasano garden centre is excellent soil for growing most things. That includes fig trees. Every bit as good or maybe better given that it's a living soil.
So, why do I pay so much for one of the gritty mixes? I'm reminded every spring and fall when I need to move all the pots out of or into the garage. I use these because they're light. That's pretty much it. I can feel the difference in my back.
All my other container plants and raised beds get bulk triple mix. They don't move much.
Yes, I use it to root cuttings because I have it on hand... and it's pretty easy to regulate the moisture but even on a layer I have no issue using the triple mix
I also find that the promix (or similar) is easy to debug and comes for the most part free of gnats etc... I would never bring bulk triple mix into the house.... especially without baking it.
I guess I can say that I like it a lot, but it's not the only thing I like. I don't really like paying for it.
What I really wish is that I could buy yards of custom blends at a decent price. The triple mix I get for $50 depending on whether I bring some capo and a loaf of bread with me.