M104w and ECOSYS M2635dw share specifications such as USB (Yes), Wi-Fi (Yes), Wi-Fi Direct (Yes), Apple AirPrint (Yes).
The main differences: Printer Functions (M104w: Print, ECOSYS M2635dw: Print, copy, color scan, fax); Print Technology (M104w: Laser, ECOSYS M2635dw: Kyocera ECOSYS laser); Black Print Speed A4 (M104w: 22 ppm, ECOSYS M2635dw: 37 ppm); Print Resolution (M104w: 600 x 600 dpi, ECOSYS M2635dw: 600 x 600; up to Fine 1200 dpi).
M104w may suit users who need its differing values, while ECOSYS M2635dw benefits those who need its paired strengths. Review the specs table above before deciding.