I print PLA and slice with slic3r, and have always just used the default of "Slow down if layer print time is below 15 seconds". I've been doing some tall slim models without infill and got sick of the wait, so I figured I'd try to push this. Right now I'm printing 100mm tall 6mm diameter spiral vase cylinder at 3 seconds per layer with the fan on, and it seems to be flawless. I'm doing tall thin prints way faster now, and so far it hasn't seemed to hurt.
Has anyone else tried this? Are there any corner cases?