Norm, on this board, you'll run into resistance stocking both, here's my experience. Some older ponds already have established fish populations where draining isn't an option, you simply manage what's there. Many Texas ponds have an abundance of bgill, often it's time to fry up the big ones, and toss the little guys out. I can say that the hybrid bluegill do get larger than the natives when fed. They also agressively hit spinner baits as well. They cross breed with the native bgill and throw offspring with brilliant colors, it wouldn't suprise me if a green sunfish is produced somewhere along the way, I have caught pure green sunfish in these ponds as well. But, in the cross bred bgill populations, while the green sunfish is a predator, it's also preferred eating over the native bgill by both bass and catfish, they make excellent bait. In a 2 acre pond, I do not have a problem with hybrids or green sunfish. I have friends who "live" for catching/eating large bgill, the negative impact of having hybrid bgill is minimal and easily managed in a small pond that is managed. While I don't have 10 lb bass, I do have 6lb bass, 4 lb cats, crappie that don't reproduce, and huge bgill and redear. I'm in the process of "trying" to duplicate this environment in a 5 acre pond + adding wipers. I'm spending the 1st year getting a heavy native bgill population in place first. Note : My management tactics aren't viewed as "by the book", I believe in selectively stocking mature "tape measure" adults with superior genitics to produce offspring for bass, bgill (both kinds), and redear's. I only buy catfish and crappie to replenish what I take out and eat.