I have no doubt that bass can grow rapidly under ideal conditions. If you've ever planted fish in a new pond with an almost unlimited food supply you will know they can grow explosively.
As far a smallmouth vs. largemouth, I have seen rapid growth with smallmouth in my pond too, although not with the lastest group I bought from a different source.
I purchase 50 to 100 five to seven inch feed trained largemouths every year and put them in a large floating cage initially to keep them from being eaten by the larger bass in the pond. I've had 5 to 6 inchers go to 10 to 12 inches from May to August although that was the maximum with many a little smaller.
