I'd like to comment on this, as it comes up regularly.
We have tested this, as I would hope would be obvious. We learned two things: (1) For most automations it makes no difference what the power of the hub is; the hub's overall performance is ultimately limited by devices and mesh network performance, things that have nothing to do with the hub itself. There is no such thing as improved "Zigbee and Z-Wave I/O capability" other than breaking these networks down into multiple networks running on separate hubs. (2) We were sufficiently disappointed with the lack of improvement overall, that we were fairly convinced that anyone paying more for a more powerful hub would not be happy about the purchase.
The business case for a more powerful hub is very weak. The number of users who would benefit from it is small, a small percentage of customers. The cost to produce and market such a product would not yield desired financial returns to justify doing it. The opportunity cost to our business would be high, when we are pressed on other fronts. All in, it's a loser for us. That coupled with our experience of the actual level of improvement in performance argues pretty strongly against pursuing this.
Having said that, we do intend to pursue steps to improve hub performance. Some of these are already done, and will show up in the next release.
