Seabass and genetic engineering

So the story is out, Singapore is breeding "super sea bass". http://www.feedsyndicate.com/articles/7008730690

The sea bass is said to be hardier, bigger, and grow faster. The flip side is, according to some gourmet critic and chef, a less firm flesh. Apparently, the lay man theory is that the fast growth cuts the time needed for the muscle to strengthen the flesh.

Reading the theory, I wonder about what will happen to the genetically engineered food items that are to grow faster as well. Although the sea bass is arguably not genetically engineered but merely selectively bred, the flesh of the "normal" sea bass and the "super sea bass" is apparently different. Considering that there should be a maximum DNA replication speed that could be hard to surpass, there should be a theoretically highest possible cell growth rate. If the cell growth rate has been maximized by the genetic engineering, shouldn't it mean that harvesting the food stuff shorter than an optimum time might actually compromise the quality of the items?

It does makes sense for longer period of growth to produce firmer muscle in the fish. What about corn? genetically modified cow, etc? In the effort to produce food faster, it's not far fetched to think that perhaps the food items are not entirely the same as those wild type that grows naturally. I wonder what else changes in the fish and future genetically modified items besides less firm flesh.