I've had a cord end type that has been on the end of the cord since April 2011. No problems with weather, growing legs or anything else. My coach has very little room for installing a hardwired model anywhere between the coach end of the shore power cord and the AC breaker panel.
What ever you choose, hardwired or cord end, just don't go low cost and install a model that offers only surge protection. You want all the boxes checked. Low/high voltage protection, delayed power transfer, pedestal wiring faults, open ground and such along with surge protection. And pretty much all the new versions of the hard wired models have simple bypass feature should there be a problem.
2006 Hurricane 31D built on a 2006 Ford F53