I'm not at the skill level to even know what to track yet I guess.
For background I shoot IDPA in SSP as a SS. I'm knocking on the EX door pretty hard but last week's State Champ match humbled me. I was accurate but really slow.
I don't take many notes but things I do write down on my score sheet for that stage might be;
fumbled re-load
bad grip during draw
gun malfunction
waited X seconds for a moving target to present
anything notable about the stage that was either good or bad
extra shots I took that in the end weren't necessary (Vickers count and was actually good but shot extra rounds anyway to be sure)
I don't get into the specifics on the time like splits, etc. I just shoot and figure out where I can improve ... or where I just F'd up mentally of otherwise.