The first thing that I can tell you is that a lot of the information that you find on the internet about orchids is NOT accurate! Why? I suspect it is because anyone can post opinions and they really lack experience to form any solid opinions.
I would never consider information found there unless it was a site totally dedicated to orchids. Totally!!
Next. Orchids and their roots can adjust to a new media easily. The new media doesn't cause the stress! What causes the stress is waiting too long to repot! Or repotting orchids at the wrong time. By wrong time I mean specifically Cattleyas, in particular bifoliate Cattleyas. The correct time to repot them is at the precise time that new root growth begins. NOT when those roots are more then a 1/2" long. When they are that long, they can easily be damaged or broken and even die. So it is NOT wrong or new media, it is the wrong TIME!!
Dendrobiums have VERY fine roots so their media needs to hold more water. They generally do not like to be repotted. They do not like their roots disturbed. So again, it is about timing, NOT media!!
Lastly, orchids like Phalaenopsis and Paphiopedilums love to be repotted. They respond quickly to the repotting by making new roots. They are very forgiving about the type of media used.
I have come up with one of my famous analogies for you to consider. I you were facing a serious operation, you would search for the best, most experienced doctor that you could find and afford to operate!!
You would not pick one fresh out of Medical School or pick a doctor who does surgery, plumbing and fixes cars! GET the best information that you can from the best site that you can. DONT get information from some random site who has formed their opinions on very little experience!
Trim roots back to live tissue. Dust with cinnamon.
