Looking at the last chart, Cinebench energy usage, the "energy efficent" cores are in practice less efficient than the P-Cores, and less efficient than all the Zen 3 CPUs, when you actually need to get some work done.
And when you enable both the P-Cores and the E-Cores, the energy usage drops by just 3% compared to using just the P-Cores. Is this worth the hassle of having to deal with all the quirks of a hybrid architecture?
Even in the single threaded SuperPI energy test, the E-Cores were barely more efficient than the 5800X cores.
While the big/little architecture had some success in the mobile device market, I don't think Intel's implementation is worth the hassle for the time being.
That being said, if I was looking to build a new computer from scratch, I would consider Intel, since the P-Cores give the best gaming performance at the moment. But, even if I bought an Intel CPU, I would probably disable all the E-Cores, to make sure the thread scheduler doesn't mess up.