I'm not sure blues will grow faster at least initially; I'll bet Todd Overton can answer this down to the centimeter, and if he doesn't chime in here because he's too busy delivering fish, you might PM him.
Main advantage to blues IMHO is also the main detriment, depending on your point of view-ultimate size and predatory capacity/inclination. Other advantage is the opportunity to catch a really big fish.
I have several >20lbs in my ~21/2 acres. With a lot of forage available, they've been fairly good citizens. I have started feeding this year, and the blues eat well, which will hopefully reduce their predation somewhat. I've also stocked tilapia and am transfering a bunch of big BG in hopes of boost forage even more.
Hope this helps, maybe some of the real experts will enlighten us further.
