[th0br0]

It's not a matter of water consumption, but of cost due to power consumption.

[seangrant]

If you're adding a projector and computer to your shower routine, you aren't too concerned about power usage.

[sokoloff]

The electricity used by those will be dwarfed by the energy used to heat the incoming water. A large electric tankless heater (served by a 240VAC/100A and drawing 18kW) can supply a 2gpm showerhead.

Compare that to a computer and PJ, several of which can be comfortably serviced by a single 120VAC/15A circuit.