I don't necessarily play a "hard" shot, but say I had a shot that needed to go 160. Possibly could get on with a 9i could also get on with an 8i for sure. Looking at the hole, depending on where the pin is lets say its in the dead middle of the green. So I see bunkers protecting the front of the green but its ok to miss long, I would go with the choked 8i. But water in the back and being long means death, i would definitely hit a 9i and try to put a good normal swing on it and just try to get on.
Really depends on my situation, I dont necessarily have a "hard" shot but depending on the trouble and how I choke down I kind of plan for my worst case scenario.
Which brings up another point. Unlike some people I can plan / play for a worst case scenario and it not get into my head. Sometimes people I know if they think something will happen thats exactly what happens. Lol that doesn't quite happen to me... but I don't dwell on it. I'm like damn, DONT miss long let me take this 9 instead of 8 bam, magic happens.