HL-5070DN and DCP-L5500DN share specifications such as Automatic Duplex Printing (Yes), USB (Yes), Ethernet (Yes), Product Brand (Brother).
The main differences: Printer Functions (HL-5070DN: Print, DCP-L5500DN: Print, Scan, Copy); Print Technology (HL-5070DN: Laser/LED, DCP-L5500DN: Laser); Black Print Speed A4 (HL-5070DN: 18 ppm, DCP-L5500DN: 42 ppm); Print Resolution (HL-5070DN: 2400 x 600 dpi, DCP-L5500DN: 1200 x 1200 dpi).
HL-5070DN may suit users who need its differing values, while DCP-L5500DN benefits those who need its paired strengths. Review the specs table above before deciding.