I looked back a bunch of pages and the only side by side pics I saw were from James the Cat but I think that was with a custom not Sideshow's ESB/ROTJ version
I'm not hoping SS will "still look good" after seeing it next to HT, I'm actually routing for progress and for the HT one to look better even if I hold off and wait for HotToys to do a ESB or ROTJ version. I am sure this HT Vader does look better (glove aside- that's really killing it for me), I'm just curious about how much better and it's hard to tell that without a side by side view under the same lighting and camera conditions.
I can't say there is no temptation to get it, hey and who knows, I've caved before on things I was trying to hold off buying. But I've also managed not to cave and to appreciate figures I don't buy from a far through photos and appreciate how 1/6 figures keep getting better by seeing comparison shots of things I don't have. I still like my SS Vader, I don't think it is so bad that I can't live with it a while longer. My feeling is if the HT ANH one is a lot better, just think how good the next Vader will be after they take a second crack at it. I think that might help me wait more than anything.
I think the biggest temptation for me is to fall in love with the specific ANH look and want to get this to pose with my new HT Kenobi - If I gave in I would end up with two Vaders one day upgrading my SS one for a HT ESB/ROTJ version too.