I think it has to do with what's important to you (the car magazine reviewer).
That slants your view of which is better. Both cars apparently approach the "sports sedan" concept slightly differently. The BMW--more power, bigger, bit roomier, a bit better cruiser. The Caddy--essentially an e46 with a craptastic automatic transmission and a somewhat underwhelming engine.
To an imperial city, nothing is inconsistent which is expedient.
--Thucydides, 420 BC