.. Works great, but beware of the
temperature. (It gets REALLY HOT). Also, be aware of your flow rate, we
had to change a few aerators (sp).

As far as venting, I would vent it out the side of the first floor as
long as there are windows close...

Could you elaborate?
Temperature; too hot or too cold?
Flow rate; seriously reduced? I'm running an 85 psi booster, I hate
wimpy water pressure.
Vent; I plan to run it out the wall behind the unit, curious if I need
to get it above the roof.