I am glad you like the new sensor. Mounting holes are something the mechanical engineers always try to push for more of, but making the board compact is often a competing factor.
The carrier board for the sensor has capacitors to help with noise and should be significantly better than the older GP2Y0A02YK0F. However, the noise is also dependent on your setup so adding additional capacitors might help.
Thank you for the kind words. We designed the brackets to be compatible with the smaller extruded aluminum systems from 80/20 because we have seen several of our customers use them in their projects.
We enjoy hearing customer feedback and how our customers are using our products; it helps us make design consideration for future products. Feel free to share your project on our forum in the "Share Your Projects" section.
In the email you sent to techsupport, you also mentioned that the noise was about plus or minus 5 feet. I am not sure it is possible to get both the accuracy and response time you are looking for. You could do more averaging to smooth out the reading more, but this will increase the delay before a change in height is detected. For the plane flight in this blog, the averaging was done over several seconds since response time was not an issue. You might have a better chance of using the LPS25H pressure sensor as it is generally less noisy so using it might help, but I would not expect it to be that much better. This blog post about the LPS25H might be useful when comparing the LPS331AP sensor to the LPS25H sensor.
In general, we usually recommend using a motor driver that has a continuous current rating greater than the stall current of your motor. From the motor specifications I found on this website, it seems like you should be able run two of those motors from each channel on the VNH5019.
I tested our Spring RC and Parallax continuous rotation servos over an update frequency range of 50Hz to 200Hz to see how they were affected. The only change in performance I noticed was that at slow speeds the servo moved a little bit faster with higher frequencies. However, the change was not a significant jump in performance, and changing the frequency had no effect on the top speed of the servos.