Had the M2 in for service and they gave me a 2020 m240i, thought ya'll might be interested to hear what I thought.
My M2 - 2018, M-Performance Exhaust, DCT, 18k miles had it since new.
The m240i - 2020 (40 miles when I took it !!), AWD, M Performance Exhaust, 8 speed automatic.
My brief thoughts on the 3 days I had it... I'll leave aside things like resale value and maintenance because that's been beat to death.
Suspension - The M240i suspension is a little better in terms of comfort while in town, but at speed on the highway I found it to be awful on Seattle freeways. The M2 is tight but feels confidence inspiring, on the M240i in the 99 tunnel at 60-65 mph for example I was being bounced around like crazy. This really surprised me, I expected it to be more comfortable all the time. It felt like a cheaper M2 in that regard, not like a more luxurious M2.
Chassis - The M240i felt 'fine' but is clearly not as planted, I felt like I could throw the car around but it's not as confidence inspiring as the M2. The M240i is fine for most people i'm sure, but I wanted a gokart and that's what the M2 is for me.
Engine/Power - M240i was surprising with the B58, that engine in modes up through sport has really nice low end pull but is lacking in the higher end. In sport plus that problem is gone and it gave me grins all day. Curious from a dig what would happen, but I suspect the m240i is right there with the m2 in terms of speed. The M2 feels a lot more violent when it accelerates, and the m240i is clearly tuned to be on the smoother side.
Transmission - M240i transmission was very smooth, 8 speed is nice and when compared to the 7spd DCT in the M2 most people would probably prefer it. It felt nice, shifted smoothly and quickly, and didn't chatter/clunk around at all in low speed like the M2 does. Of course the DCT shifts faster and in theory holds more power, curious to see how this transmission does longer term.
Sound - The M240 I had was equipped with the M Performance exhaust, and I was a big fan of the sound. Very smooth, good tone, and no drone at all (it was new so maybe it'll start droning..). I really like the valvetronic on the M2 allowing me to be quiet or loud, but the M240i would be just fine as a DD sporty car.
Steering - This is where the M2 absolutely dominated the show for me. I found the sport+ setting in the M240i to be less stiff than i'd like. Sport+ in the M240i was close to the comfort setting in the M2. M2 wins this area for me by a wide margin, as expected. Will see about a RWD M240i next time it's in if they'll let me
I have my own biases of course driving and owning an M2. Overall I was really expecting a significantly more refined M2 for the price point this cars in before driving it. I found it to be in some ways an 'almost there' sports car (suspension, steering, chassis) which was a little disappointing, and in others (i.e. transmission, b58, etc) it delivered the 'luxury' I expected.
We could debate til the cows come home what is the better car, all in all I'm glad I bought the M2, and I can see why people buy an M240i. There's a clear division between these cars when BMW was making them of the focus, and the M2 is the focus I wanted them to have in building a car. I would really suggest anyone that's on the fence to drive both. While that might sound obvious, i'm amazed how many people don't.
The main thing I took away from this experience personally, was that when the S58 hits the M2, I'll consider filling my empty garage bay with one...