You could use any type of inverter based on NPN transistor or Mosfet.

In some situation SERIN (or any else bit-banged solutions) are nice, sometimes they're a pain.

Using the PIC USART have poor and cons. Well, the only 2 small cons I know of are:
1. it use a dedicated PIC input (oh... big deal )
2. Not all PIC USART allow you to use only TX or RX for the USART, and the remaining pin for standard I/O.