Everyone's going to be trying for the FE, with the prices of the AIB being so much more
Depends on reviews of the FE - the 450W 3090ti FE was a very loud card, the cooler wasn't appropriate. I'm happy to pay more for a quieter card. I'd watercool my GPU - but having to hear the pump when GPU is idle means 0db idle fan mode for air cooled cards is best for me.
4090 FE cooler is larger than the 3090ti FE cooler, though the AIB cards being so much larger still means they have larger heatsinks, more fans, so will be quieter and cooler.