Haven't tried anything else, that is removing the ER, moving the Smoothlan to upstream etc. to what I stated above. But going off of memory from many months ago, so take it with a grain of salt, to the last time I re-tested the ER by taking it in and out, what I am getting by adding the Smoothlan to the exising chain with the ER is a much bigger uplift than adding the ER with a Plixir linear PS.
These ethernet tweaks are so system dependent, that is the beauty of money back guarantee's, but what I am getting with the Smoothlan is way beyond the vocabulary of "tweak".
I saw the video posted above from the Aussie guy, never seen one of his videos before and haven't seen any since, but it was a few months ago so don't completely remember what he said, but I recall he had quite a nice setup, and was completely over the top, and the skeptic in me thought to myself I have seen this before- He sounds like Huff with all his " Wow! this is the best ______ I have ever had!!!!!!!!!!!!" until next week when he tests something else and says the same thing. But Aussie guy wasn't kidding- this little block of British alu-min-yum is the real deal- at least it is in his and my system.