Nvidia Shield TV 16GB vs 500GB performance comparison

Hi all, so I've purchased the Nvidia Shield Pro (500GB) model the other day and noticed the device made some slight disk spinning noise, only to realize that this console comes with an HDD rather than flash memory. I also noticed that even thought this device is still running lollipop, I'm still able to utilize any one of the external ports as the default memory.

This question is mainly for those of you who had the opportunity to try both models. I'm not a fan of HDDs much, but the voluminous internal storage is convenient in a way, although I could easily do without it, if the 16gb is the more stable model. From my experience NAND flash based devices seem to run fast, but are they noticeably faster than their hybrid HDD counterparts? Is there any difference in speed and performance between the 16gb and the 500gb Shield TV devices? I'm asking because I noticed the Shield controller's home and back buttons don't always respond, and my device is running build v2.1 which supposedly fixed any known controller bugs. I'm tempted to return the 500gb and grab a 16gb just for the sole fact that the Pro model runs on dated hard disk technology, not to mention the faulty HDD units in some of these models. Let's hear some opinions on this, I've not found any comparison on these from a performance perspective. Every comparison I found so far brags about how advantageous 500gb is over 16gb, but no one seems to compare their performance side by side. So if you've tried out both variants, do you find the standard 16gb edition to process data quicker than the Pro model, and are you experiencing any unresponsiveness with the back and home buttons on shield's controller?

Just ordered a 16gb Shield TV Console from GameStop. Since no one's chiming in on the topic, I'll have both versions in a few days and will post my findings after testing them side by side.