HL-5240 and HL-L6200DW share specifications such as Printer Functions (Print), Print Resolution (1200 x 1200 dpi), USB (Yes), Product Brand (Brother).
The main differences: Print Technology (HL-5240: Laser/LED, HL-L6200DW: Laser); Black Print Speed A4 (HL-5240: 28 ppm, HL-L6200DW: 48 ppm); Automatic Duplex Printing (HL-5240: —, HL-L6200DW: Yes).
HL-5240 may suit users who need its differing values, while HL-L6200DW benefits those who need its paired strengths. Review the specs table above before deciding.