XTR RD 980, would mid cage fit on 36 cassette or long cage?
What chainring setup are you running?
When under pressure, your level of performance will sink to your level of preparation.
2 x 10, something like 42T max front with XTR RD shadow?
This thread should answer your question. You need to compare the rated capacity of the derailleur to the gear sizes you will be running.
When to use a Long Cage vs Short Cage Derailleur?
Looks like long cage for my setup, 36t cassette is huge. I can probably use the mid cage but at a cost and has anyone tried it?