They are both great cars, but are in different categories if you ask me. The Lexus IS-F is an amazing car, it is very refined, safe, and fast. The same goes for the 5 series. BUT, they are different types of cars. The Lexus is a high performance car. Whereas the 5 series is a lless agressive sedan. Trus it has good power and can have a sporty feel, but it's just not the same. It all depends on what kind of car u are looking for.