I had a bit of a think about it.
High capillary means pots that drain water out faster.
What is the advantage to disadvantage to a low capillary pot?
Depends on what plants can tolerate higher amounts of water for example a low capillary pot gives off more water capacity in a pot while a high capillary drains faster.
There are certain kinds of plants that can take higher amounts of water and lower amounts of water.

There is also a medium capillary pot that can give off more and less water at the same time depends on the plant.
I can show you pics of the type of pots I am talking about.
One that has a one hole in it and one that has multiple holes in it. All in use for different purposes but can all operate the same for good growth of plants through water.