Netzari Emunah Siddur
Tehillim 1:2 But his delight is in the Torah of MarYah, and on His Torah he meditates day and night.
The Netzarim follow Nosach Sefarad and Nosach Teiman because the Teimani (Yemenite) tradition–liturgy, halakhah, and culture–best reflects the 1st-century practices endorsed by Ribi Eashoa' Msheekha (Christians refer to Him as Jesus) .
It is the oldest tradition, the least tainted by external forces, and therefore the closest to Har Sinai.