Here is an excerpt of the BMW M4 Convertible review by Autoexpress.
Verdict: 4 Stars
The M4 Convertible isn’t quite as sharp or as fast as the Coupe, but then the drop-top versions of performance cars rarely are. What matters is that people still buy them, and anyone in the market for a driver-focused four-seater convertible should put 
this BMW at the top of their list. Performance may take a slight hit, but being able to enjoy sunny days and hear more of that fantastic engine are worthy trade-offs.
The M4 Coupe might be getting all the headlines, but don’t forget the new M4 Convertible – BMW is expecting nearly half of M4 sales to be of the drop-top kind. We climbed behind the wheel to see if those buyers are getting a car that’s just as impressive as the Coupe.
The folding hard-top features the same 425bhp 3.0-litre twin-turbo straight-six as its fixed-roof sibling, so the performance is clearly very similar. But it has the disadvantage of a 178kg weight penalty. In lesser versions of the 4 Series Convertible, this feels like a serious problem, although in the M4 you can barely spot the difference in straight-line performance.