Hi Pillairp, With my limited experience i will try to relate to you what works for me. Half of my plants are mounted so that is a no brainer, the other half are in plastic and clay pots. My milts, oncidiums, dends., and paphs. are in plastic and i us Aussie Gold for all with great success, my phals. i use a bark and moss mix with sponge rock and charcoal.
I have (2) large phals. in plastic pots and the rest about (20) in clay. I will say and i know that many disagree, the clay pots out perform the plastic, i also tried cocochips, unsuccessfully. Good luck Hank.....