Our X3 M40i 2019 (EU, 354 hp) feels a lot faster too.
There has been multiple dyno tests with the X3 M40i:
stock X3 M40i 2018 (UK, 360 hp), result: 394 hp
https://x3.xbimmers.com/forums/showthread.php?t=1558623
stock X3 M40i 2020 (US, 382 hp), result: 399 hp
https://x3.xbimmers.com/forums/showthread.php?t=1558623
I think the M340i will have been tested extensively at their forum.