I have had to re-pot my Ang. mag, didieri and some others. I just follow the rules I posted earlier. I do agree about doing it just before the summer weather starts.
If the medium is bad, you don't want to leave it in there. These do like more air around their roots so a compacted medium can equal death.
Ok lots of good advice here. I will give it my best shot. I received another species of Angraecum today from Lehua. It's a very large plant and it's about to pop the 4 inch pot its in making me think I might be able to go another blooming cycle before repotting the plant we have been discussing. Amazing to me how such big plants can survive in such small pots.
I repotted mine during the winter, as the grower grew it in sphagnum in a plastic pot with usually equals to rot in my conditions. Unfortunately, It was so potbound that I couldn't remove the media and accidentally cracked one small root. Hopefully, it will do well in its medium orchiata bark mix in an air pot.