M3027 and MFC-L6750DW share specifications such as Print Technology (Laser), Print Resolution (1200 x 1200 dpi), USB (Yes), Ethernet (Yes).
The main differences: Printer Functions (M3027: Print; Scan; Copy, MFC-L6750DW: Print, Scan, Copy, Fax); Black Print Speed A4 (M3027: 25 ppm, MFC-L6750DW: 48 ppm); Automatic Duplex Printing (M3027: —, MFC-L6750DW: Yes).
M3027 may suit users who need its differing values, while MFC-L6750DW benefits those who need its paired strengths. Review the specs table above before deciding.