I opted for the hardwired EMS 30 for our 23IKSS. It is installed on the inside front of the bathroom cabinet. That is where the power comes in from the outside, and there was plenty of slack wire to splice it in. As pjnlorrie mentioned, Turbs has some great installation pictures where he used 30amp plugs and I followed his lead. Using the plugs makes it easy to:
1) remove the unit if you sell your RV
2) bypass the unit should it ever fail
Essentially, you get the benefits of a portable unit without having to worry about theft. I know some have concerns about installing it in the bathroom cabinet, but when I looked at all the potential installation options, this made the most sense. There are so many places in the RV where water and electric lines are close together I wasn't really concerned about the EMS getting wet.
I live with fear every day, and sometimes she lets me go fishing.
2015 Shamrock 23IKSS
2008 Ford Expedition EL