I have the same experience. I am using a Raid 0 NVME Storage pool consisting of 4x2TB 970 Evo Plus's just for the PROJECTS pool with all the WS's running 10gbe Nic's and 10gbe cabling throughout the whole office.
The 10gbe speeds are completely saturated during simple copy/paste file transfers yet in real-world use, at least for "US", there is absolutely no difference.
Now I could sit here and write 5 other pages on how I tried several configurations from running Raid 5 and 6 on standard HDD's to running single ssd's and finally running a raid with Nvme m2 ssd's but this should be as simple as possible. I assume this would only be interesting to a few "geeks" of us here and most people wouldn't understand and I don't blame them. I myself lost a lot of time to learn this and in the end, it turned out to be a complete disappointment in both performance and my wallet...
I tried every possible test that suits our workflow. Scene loading times vs 1gbe, Render node loading times vs 1gbe, Photoshop, you name it :). As I wrote before the most important thing is always the CPU and it comes ahead of everything (network, ssd, ram) the faster the cpu the faster the loading times will be :).
Just by changing our old xeons from the farm with newer threadrippers we have seen a massive gain in performance. Those machines work on a much higher boost clock than the Intel Xeons and load heavy scenes ( we had files of around 3-4gb in size ) much faster. A quick real-world example would be that we used a Dual Xeon Platinum 2x24 core machine as a Backbruner Server with DR rendering on. This machine vs the 3970x took sometimes even up to 15 minutes just to load a scene and start rendering while the 3970x did the same scene loading in 5 minutes. We had to deliver 18 images that day in 5k resolution. 18 images X 10 minutes more time to load on a Xeon machine is 180 minutes more spent on just loading the same scene 18 times over on a different machine. In my book 180 minutes more is a lot of time lost in an 8-hour working day.
I haven't compared exporting the passes at the render end and saving those big CXR files. But at the end of the day how many times are you doing that during your whole working day? It's not even a tiny 1% of your time so who cares if it's a few seconds more right?
I burned a lot of cash on this 10gbe venture and to all people who plan on doing the same and still using the same software (99% of us use on this forum -3ds Max, Corona, Photoshop), mainly for 3d visualization purpose I say, save your money and invest in a high-end workstation or a rendering node instead of wasting it on something you won't get any real benefit.
Now I suppose Juraj will write (as he did before :P) that I am completely in the wrong with this one and that he has some amazing performance gains. But from what I see I am not the only one complaining about this and I have no real reason to lie either :). On the other hand, if you do video editing then this is definitely the route to go since those tasks mainly use sequential read and write operations that fully benefit from 10gbe speeds.