The M340i is a legit enthusiasts car for the price. The M3 is obviously a step up and the S58 has the potential to be a complete monster. I have driven the 2020 M340i for the last year and I love it. It sounds very aggressive when in sports +, but then quiets down to a normal luxury sedan if you want. I did not expect to upgrade to the M3, but after a while the BSM color on the G80 kept growing on me.
I went and test drove a 2021 M3 Comp and I just decided to do it. It is just like the M340i interior, just a little better. More top end and more customization with the driving experience. The gap between M-Lite and full M gets smaller ever time a new version comes out. I don't think there is a wrong choice here, it just depends on your personal preference and driving style.
I have pushed the M340i, it is very capable on the track and it will hit the 162mph limiter no problem on the Autobahn.
