it's been documented that liquid designs require more time to develop because you have to trial and error the sizes so that it fits the same mockup. some clients are particular on the size.

liquid design's were really great because it allows the layout to expand therefore the ability to reveal greater content of higher value.

liquid layouts are still being experimented by international designers today. they are trying to use DOM so that if a person's screen is more than # width, the layout changes in a particular way.

i think liquid designs are best used when the website has too much information to hold and require maximum space for usage.

for a designer, liquid might work pretty well because you'll want to take advantage of screen space and showcase the bigger picture.

cheers.