The only downside of a rootbound ülant I've seen so far is the plant had to be fed constantly, several times a day an most important, roots needed to be moist all the time. And that was in soil which I started treating just like coco except for the pH. The upside was the plant grew at a ridiculous rate. So I left that plant dry out only once for half a day and the plant was dead the day after no matter how hard I tried to bring it back. That same plant was in a 0.8l pot and grew at a higher rate than my other plants in 12l pots that got fed every other day. This just confirms the explanation in that post I quoted and the findings in the thread I linked where the post is also comming from. It also explains why there's no salt build up in the medium.
You should really read everything in that thread before you start calling people names and what not.
I'm not trying to bash you or anything, just trying to open your eyes and have a look out of the box.