The question of substrate is a highly individual one. It depends on many factors, such as lighting, humidity, how often you water, what types of extremes you need to overcome, etc.
I use cedar bark mulch, medium orchid bark, pumice in equal ratios with a little charcoal mixed in (<10%).
I hate repotting plants grown in sphagnum, because, inevitably, under my conditions, the sphagnum begins to break down and get sloppy and I end up spraying the root ball with my garden hose to remove as much of the mush as possible and end up loosing some roots too.