Luck with your particular card sample may differ. Having large rad area also won't do wonders, it will mean that air/water delta will be low even with relatively quiet fans, as one cannot get temps below ambient with LC, so even more powerful fans .. maybe 5C less, then less rads & slow fans, but will it be decisive to max o/c? Doubt it.
Then again, LC will be more effective then air (especially then one that is so handicapped, to dissipate 400-500W within small air cooler dimensions, unlike eg. 200W of much larger top cpu coolers), and having LC waterblock made will help a lot those that will use card for actual gaming, not just few max overclock tries, as with better cooling it's possible that a bit less extra voltage will be needed for same clocks and thus electricity bill will be more reasonable, card will throttle less because lifted cooling limitations, and noise will be much quieter/acceptable for home use.
Then again, LC will be more effective then air (especially then one that is so handicapped, to dissipate 400-500W within small air cooler dimensions, unlike eg. 200W of much larger top cpu coolers), and having LC waterblock made will help a lot those that will use card for actual gaming, not just few max overclock tries, as with better cooling it's possible that a bit less extra voltage will be needed for same clocks and thus electricity bill will be more reasonable, card will throttle less because lifted cooling limitations, and noise will be much quieter/acceptable for home use.