We kinda went through the same reaction when ours was new, Homer. After a few showers we got used to it, and became aware of the intruding handle enough that we rarely bump it anymore. Our showers at home have rotating on/off and temp adjusting knobs that don't protrude and I'm sure that style could be used to replace the RV shower valve. But shower valves can be recessed enough to make the retrofit no easy job. For us, after getting used to the existing valve, such a changeout is now not on our minds.
Nevertheless, both Delta and Moen make rotary valves that are good candidates, like this example: http://www.faucetdirect.com/moen-2352-single-handle-posi-temp-pressure-balanced-shower-trim-and-valve-with-single-function-showerhead-from-the-chateau-collection/p47441
Joel and Lee
