However, if you live in a warm climate, such as Texas, Southern California, Florida, Arizona, etc, then you probably do not need to raise the water temperature by 45 degrees, so the 1000P can work for a single shower.
Also, if you use a low-flow shower head that reduces your flow to say 1.5GMP, then again you can have a hot shower with the Bosch 1000P.
We would not recommend the Bosch AquaStar 1000P for a regular flow shower head in New York -- it just will not be able to keep up and provide you with a hot shower.
The Bosch 1000P replaced the older Bosch 38B. But the 38B only delivered about 1GPM at the same 45 degree F temperature rise. So, the 1000P really is a much stronger water heater than the 38B ever was!
The Bosch 1000P comes in both Natural Gas and Propane models.