Great to hear you’re enjoying it! The Queen ER version is a square-wave clock but I’m not sure if the higher end models are. From what I understand getting a square-wave right is not easy and in many cases a good sine-wave with the appropriate filter is the best way to go unless the clock truly is doing a good square wave (like a Mutec).
John Swenson has a great paper on this topic: paper
You have done your homework too 
I read regularly Audiophilestyle forum and John and Alex thoughts about these things too. And since they work with collaboration with AfterDark,I think all offerings from AD are good too
I don’t think they collaborated with AD although AD is their HK dealer. They did say that upon inspection they do think the AD products are good quality tho.
So what are your thoughts? Better to stay with this Queen square wave,and it´s as good as it gets for ER…or go for higher end Emperor sine wave clocks?
I’m in a similar quandary but I’m leaning towards an Emperor sine wave with the filter given 1. John’s comments about the complexity of getting a square-wave done correctly and 2. sine-wave doesn’t require such a high end cable as a square-wave does, one less thing to second guess myself about. 
I will wait a little longer to hear more user reports before making a decision.
There will not be many who goes through both square and sine wave clocks and will have a definitive answer which clock or package is best for everyone. There are so many variables in play starting from ones system and how ER is powered,all cables etc…just too many variables. Johns last chapter pretty much sums it up. Square wave will be the best for ER if things are done right. Well I guess AD have done things right with Queen.
I call it a day for my part and enjoy Queen now. I have no hurry to jump higher end Emperor models though 15db lower phase noise levels at 1Hz are tempting.
But maybe later if general wisdom and experiences show that´s the way,sure ! 
Edit: So much for living in a dark I asked straight from AfterDark their opinion.
They have very fast and good support and I was answered immediately fully to my questions and here is the wrap:
Emperor Double Crown with their Black River BNC cable is the best for ER. No need for filters etc…but there is a small caveat as always…they can produce only 5 units per month.
This AfterDark sounds interesting. Something to look into.
Today my brother came over to see what this ER is all about. He doesn’t think you can hear any difference on a stupid switch that’ s so outrageously overpriced. Well, he’s a believer now. The sound was duller and more veil without the ER. The Farad power supply helped it even more. But the darn thing broke while we were testing. The dc connecter broke off the circuit board. It’s pretty flimsy, so be careful plugging the power supply in and out. Right now I have the connector clamped on with a C-clamp until I find a way to solder the darn thing. It works fine with the clamp but I can’t put the cover on all the way so I’m running it air cooled.
Anyway my brother don’t need a ER because his Aurender runs off the internal memory drive. not a NAS. It’s suppose to sound better than a NAS drive.
I am actually thinking I may no longer need my EtherREGEN either. At the moment my only networked device is the Pink Faun server and I am feeding it fiber optically. I can’t imagine the EtherREGEN helping in this situation.
One nice thing though, the output bridges on the Pink Faun have external power supply inputs and I believe a Farad supply need to be ordered to see what that brings to the game. Fun.
Nope, you don’t need a ER, but you really will have fun with a Farad though.
My brother couldn’t believe the SR Galileo power cord he heard at my place sounded so much better than his Tara Labs Colbalt last week that he brought it over again along with his SR CTS and Cardas Clear Beyond XL and did another shoot out.
The Cardas and SR CTS were really close. The Cardas being slightly clearer and fuller. The Tara Labs is better than both the Cardas and SR CTS with a even richer and more open sound. The SR Galileo still beats them all with the biggest difference in transparecy, resolution, and liveness.
The SR Galileo power cord is really something, but their Galileo interconnects which my brother had before isn’t as good. His WW Platinums 8s are better. He already sold those Galileo interconnects. Strange that SR’s interconnects canot match their power cords in our systems. Though it is interesting to share this experience.
I also offer free EtherRegen storage same as the Sonore Ultra Rendu SE storage. 
I have a Micro, Ultra, and Signature Rendu sitting on the shelf. It seems wrong
I was thinking about doing a Sonore to see if fiber makes a difference and isolating the Ethernet away from the main rig. It’s between that and a Auralic G2 running WiFi.
Ya know, that G2 is an endgame piece. If I had it I would not bother thinking about any replacement. Is there something better? Sure. But who cares?
[Thread Revival Alert]
I have a used EtherRegen on the way.
Any of you early adopters still running with one; and do you have any words of wisdom or experience you would like to share?
Cheers.
I had one. Bought it just as all of the Covid fun began. I did not find that it made that much of a difference. At best, a slight improvement over a run of the mill switch. That said, I kept it for about 2 years and sold it in the summer of 2022 for a bit less than what I paid for it. Replaced it with a Waversa switch; which made a much more noticeable improvement.
I found that the EtherRegen ran really hot. While the manufacturer says that’s normal, I still bought a little usb fan (virtually silent) on Amazon that I plugged into an old apple charger and put it on top of the EtherRegen. It did a good job cooling down the EtherRegen. I recommend getting one.
i also did the EtherRegen during covid and added an afterdark kit on to it AfterDark. Project ClayX Black Modernize Thermo Kits for UpTone EtherR
interestingly Auralic go on around using Wifi just got the new Aries G2.2 - and i’m running a full ubiquiti network to the EtherRegen switch and im sorry its better than connecting to my Ubiquiti Wifi …
may play latter on but hey it work it works really well so why change it …
I still have my EtherREGEN, also with the AfterDark heat sink and power supply. I have found it essential to my streaming. Importantly, the SQ jumped when I isolated it to just feeding my Roon Nucleus +. When I had another switch in the same Ethernet circuit from my router, I am sure that added a degree of noise that cut through some of the “moat”. I’m thinking of upgrading the power supply or my internet router.
I have one with the After Dark clock and power supply. I do not have much of an opinion on it. It is still in my system.
Do you happen to recall whether adding the clock made much of a difference at the time?
Does it at least “seem nice”? 
Regards.
It does seem nice!