The combination of excellent performance and elegant design has together elevated this model's reputation.

Literal

Performance [attributive-の] excellence [and-と] design [attributive-の] elegance [subject-が] both-together [相まって] this-model [attributive-の] reputation [object-を] have-raised-[come-てきた].

Product-marketing formal prose. 両々相まって ('both mutually combining') is a literary set phrase for 'working in tandem, both together producing an effect' — four characters of pure 漢語 literary flavor. 声価 ('reputation, public esteem') is formal/literary and rare in spoken Japanese. 機種 ('model, type') is used for products like cameras, phones, computers. ~てきた marks the process as extending from past to present.