From what I have observed most bass sold larger than fry are usually pellet trained and fed anymore anyway. It's more cost effective than trying to feed them live feed.
I do know pellet trained bass will quickly adapt to natural feed if they are the only ones in the pond. As far as competing with bass on natural feed I don't know. I do know my pellet fed bass that I feed twice a day in summmer also feed on bluegills and will not hesitate to hit a fish thrown in the water or hit an artifical lure.
I wouldn't have anything else besides pellet trained bass, as it allows me to have more bass, and faster growing bass in one of my ponds. My pellet fed bass have much higher condition factors than the natural fed bass.
In fact, I will probably be bartering with a pond management company to come in an remove as many of the 12 to 13 inch untrained fish as they can. He will electroshock for me for harvest (I sell trophy fish to other taxidermists see
http://www.ligtel.com/~jjbaird/bairdfish2.htm) and he can have slower growing natural fed bass. These bass were hatched from the pellet fed bass, and are much slower growing than the pellet trained fish.
My pellet trained bass here in northern Indiana will be 10 to 14 inches in one year vs. a 4 or 5 year old fish of the same size that feeds naturally. Three pounds in three years seems to be the norm for the pellet fed fish. I will hold on to my bass until they are about 6 lbs. before sale.
However, diets exclusively for largemouth bass have still not researched enough and there is a possibility that they are not getting everything they need on a pellet diet. Some research has shown a possible lower survival rate of pellet trained bass in winter due to this but it is not conclusive. Be sure to feed them high protein feed. I feed mine a trout broodstock diet that has a large pellet size and has extra vitamins and minerals.