Can't help you re the pressure balance vs thermostatic, but I much prefer the thermostatic. Do you constantly change it because you want to, or it changes with emptying the tank and you must? I really like setting it once and just turning the volume control on. Never too hot, never too cold, but easy to change if you prefer or another person changed it - realiable to get it back to your preference. SOrt of like the memory button on the car seats/mirror, etc. Once you find your preference, it is easy to get back.
A minor direction change will not affect the pressure much so it doesn't make any big difference about which end it comes out of the valve.