[AhsanU]

Not a 340i, but I traded in an F30 335i xDrive for my M3 and regret ever wasting time with the F30.

Yes, there is a world's difference.

It's not just due to performance differences to be honest. I HATE the orange lighting all over the instrument cluster, almost as much as I hate xDrive. I love the hips and wide rear fenders that make the M3 look so aggressive, I love the acknowledgment from fellow BMW enthusiasts and car enthusiasts alike when I'm driving. I enjoy being about to dial in what settings I want for the steering, throttle response, suspension, etc.

While the performance benefits can be debated, there is no substitute for the way the M3 just feels better, and how much happier I am behind the wheel of it rather than the F30.