I have. Not fun. Even a 6" creates a challenge.
I have an electrical inspector is telling me that the 12"x12" is not large enough. I don't like challenging inspectors, BUT. He is trying to tell me that the code requires a 20"x22" minimum access. I challenged him to show me in the NEC knowing it isn't there. Then he said it's an IBC requirement. I said we aren't going by the IBC. He is still insisting on the larger access panel.
No skin off my back, the cost will be put on the owner.
He is on a tight budget and it will ruin the "clean" look he is going for with the sheetrock ceiling.