Now running for almost two months, thought it was a good thing to check on the pump at EndX, it was last checked Sept 3.  The attached trends show means over the last 60 days.  At the beginning is the period with the pump drive (motor speed, bottom plot) off the zoomed in scale as the sick pump maintains the PID setpoint differential pressure (top plot) for a couple days while we decide to change the pump.  While the replacement pump does spin a little faster than the first one, it is a different unit after all, it isn't crazy different.  And while the motor speed has increased somewhat steadily, I see a pretty clear correlation with the outside temperature and attribute the increase to the cooling mechanical room.

Bottom line--the replacement pump is performing adequately.