In this case it doesnt have anything to do with relativeness I think. It has everthing to do with what you look for in a car and what your standards are depending on how you will drive the car.
As a daily driver the oem suspension is sufficient. If you drive fast in the straight it is also doing its job well enough. But if you take it to the track or drive on the public road like you are on a track the suspension is just not good enough. Mainly because of the weight of the car.
Watch this review in case you havent already:
Although I do think springs can have a slight improvement in handling because of the fact the car being closer to the ground this is definitely not enough to make the M240i handle like a full M car. But again this might not be the wish of every M240i driver.
It was my wish because I like my cars to drive like a razor and this car has so many potential which I felt I couldnt use with toe oem suspension.