Hello,
When one wants to get an average on spot metering it means that he doesn't know how to use it !
Pentax spotmeters are very good tools. They are simple and do the job.
You shoot B&W ? Then take a reading on the shadows where you want to get details, place them 2 stops under and let fly the highlights.
You shoot E6 ? Then take a reading on the highlights you do not want to be burned, place them 2 stops over and be with it with the shadows.
One reading - One solution. Averaging is the best way to get highlights burned and shadows buried as soon as the brightness range is over your film capacities. Especially with E6 and there 5 stops.
No need to average. Just a need of knowing how to use it.
If you want to know the contrast range of the scene take two readings : one on the shadows and the second on the highlights. And as the reading is in EV, you only need to know how to do a subtraction to get the contrast of the scene.
I do own a Digital Pentax Spotmeter and I won't trade it for anything else. It does the job it is paid to do and does it well.
J