I own one of each. I've owned my M&P 340, .357 for a few years. I just bought my M&P 9 compact 2.0. It's hard to say which is better. I love them both. My 9mm is my new conceal carry gun. Replacing my 1911, 45. My .357 lives in my truck. They both shoot real nice and they compliment each other. It's hard to say which one you should buy. They're both fine guns. Since you've owned a 9mm before, it would be easy leaning in that direction. But, you can never go wrong with a revolver