I took to replace the popular S3, which also proved itself well, but as a base one, but I wanted more comfort, more speed and mileage. M4 provided all this. And 25 kilograms of weight, with all its "nishtyaks", are mere trifles, if only a couple of times during a trip it is lifted to the floor or rolled into the elevator.
Pros below:
As noted by many users - for the money you simply cannot find anything better.
It picks up speed quietly, smoothly, but quite confidently, unlike the M2 (which bareSee full review