Gains depend on the saw. Yours have been bigger gainers than some. 25–40% would likely be more accurate. For what it’s worth, 50% is twice as fast. 100% is infinity and unattainable.
Well when you listen to porters who shoot straight on what saws gain, you tend to buy those saws, or at least that’s the smart money.
I gave my new BR350 yesterday. It continues to meet my expectations. The only leaves still on trees are the oaks. Another couple of weeks should be a good test of it.