I have the 12-24.
The petal hood is insignificant, there's a round ring that u can put onto the hood before putting on the lens cap. The round ring do not result in any vignetting (at least for mi 300D), but when a filter is put, vignetting WILL occur. Quite a dumb design i'd say, as if the filter is 'lowered' closer to the lens, then vignetting shld be controlled.
quality wise, it is great! minimal distortion of any sorts. new one cost at $1100+.
in love with WA,