ISZ-1215/1315 bias performance

Several q's here:

1. The specs for the ISZ-1215/1315 look virtually identical. Any differences worth mentioning, particularly pertaining to long term stability of bias and scale factor?

2. I plan to externally compensate bias and scale factor over temperature (to -40C). I notice that -40C is outside the performance range but within the operational range of the part. Any anticipated difficulties with getting a spline fit to stick with these parts down to -40C?

3. Have you acquired any data pertaining to long term bias and/or scale factor stability? Run-to-run? Month-to-month?

4. Vibration: the data sheets seem to claim that any vibration frequency less than ~25kHz will cause little or no disturbance to the output of the sensor. Am I interpreting that correctly?

5. I plan to use several of these sensors on the same PCB for redundancy/noise reduction purposes. Will I have to worry about crosstalk between chips either mechanically or via the power lines? I am currently planning on using 1 dedicated regulator supplying several power for several of these chips but no other circuitry.

On a non-technical front, any thoughts on how long the 1215/1315 will be supported by InvenSense before they are EOL'd?

Thanks!
Tim