I actually thought Rock was a poor free taker when he was young. He was only average enough on the frees on the u21 team that won the AI. But he improved year on year and is probably the best in the country now. I don’t think the flat track part of it though was particularly correct in relation to him - pressure or the occasion never seemed to change his percentage chance of scoring.
O Connor is definitely affected by the occasion, but probably every player is. Rock is protected by an almost perfect technique / technical set up, but O Connor isn’t so clinical (from the hands he can’t be), so when the pressure invariably makes you 4% or 5% off target, it can be enough to hit the post or send it wide. Apart from the frees I think O Connor is decent, but not in the ‘marquee’ range of a McManus, or Geaney etc. As you say, he is too one paced.