Todd,
Nice write up, I have the same shower installed on my '08. It works well, the temperature setting is a little sensitive, but once you get it dialed in it is great for warming up your wetsuit or just having a nice warm shower. The only problem with these is the motor has to be running in order to get the hot water out, if you shut off the engine it will quickly cool down. Standing on the platform with the motor running is really not healthy, even with the CAT ETX motors you still get a wiff of exhaust. Maybe if you have the FAE it would eliminate this.
Let us know how it works out for you.
White/Charcoal, 2011 VLX
2008 Supra 22SSV