Often, yes. The TL-WDR7661 is a variant with a different external antenna design. However, always verify hardware version numbers (v1, v2, etc.) before cross-flashing.
The TP-Link TL-WDR7660 is a popular dual-band Gigabit router, known for offering exceptional value in the AC1900 class. However, if you have purchased this unit—especially from international markets like China (Mainland) or Southeast Asia—you may have encountered a frustrating problem: the management interface and firmware are locked in Chinese. tl-wdr7660 english firmware
No. Performance remains the same. However, English firmware may unlock more Wi-Fi channels (e.g., 149–165 for 5 GHz in the US). Often, yes