Both printers include Wi-Fi connectivity and USB connectivity. Their most relevant distinctions are colour printing and fax.
L5390 supports colour printing, whereas ET-M2170 does not. L5390 offers print, scan, copy, and fax, versus print, scan, and copy on ET-M2170. ET-M2170 has ISO black print speed of 20 ipm, versus 11 ipm on L5390. L5390 supports an automatic document feeder (ADF), whereas ET-M2170 does not. ET-M2170 supports automatic duplex printing, whereas L5390 does not.
The choice depends on use: L5390 leads in colour printing, while ET-M2170 leads in ISO black print speed. Match those differences to your needs. Consider the first model if colour printing matters most; consider the second if ISO black print speed is the priority.