Having had a sample from both manufacturers, I would endorse Skywatcher 120ED only.
I owned the NG 127ED - it's the parent company's direct export model, not rebadged by ES/Meade/ad nauseum. It holds the record for the fastest turned around/sold off scope I have yet owned - I think I owned it 2 weeks. And, that was retrofitted with a Moonlite with robofocus and it still wouldn't focus sharply worth a darn.
ES might LOOK prettier than the yak-tastic Black Diamond SW's, but looking THROUGH is what counts - and the SW will be CONSIDERABLY ahead of the ES - even the SW 100ED will surpass the ES.
I am sure I will get ES and ES Fanboy hate mail
No hate mail. I have the SW120ED, and it is razor sharp, with a trace of expected CA for an FPL53 doublet. I also owned an AstroTech version of the 127EDT, and it was sharp also, with a bit more CA than the 120ED.
Your experience may relate to how this industry works. Explore Scientific contracts with the actual manufacturer for a specified wave front quality, in this case 1/4 wave front. What do they do with the rejects, since they mass produce lenses, and likely just pick the ones that pass for ES, and then reject the others. What happens to the reject lenses? Are they trashed? How about they resell them as the house brand, along with other, untested samples. Could you have gotten an ES reject? Seems possible. When a customer requests a quality standard, something has to be done with the rejects. Since I doubt that they hand figure their optics, they would either have to trash them or sell them. Refiguring optics is not likely.
For most people, a 1/4 wave optic will be sharp in-focus. The rejects, though, will not be sharp. Neither will untested samples that fail to meet that standard. In the world of commercial optics, a name does mean something, even if the ultimate source of the product is the same. Scott Roberts and I had this conversation a few years ago at WSP in Florida, and his take was to pay the supplier a few more dollars for the product to get it right out of the factory, rather than deal with the return of a product that should never have been shipped to him in the first place. When you deal directly with the factory, you don't have the clout of the vendor selling quantities of the product under their label.
I agree with you that what we see through the eyepiece matters most, not the cosmetics of the OTA. I actually like the look of my SW120ED on the outside, though.