I like the small size of the Jupiter-3 Plus over my larger Fast-50s. I have those as well. A number of people must agree, the first batch of the J-3+ has sold out. More on the way. All three of my Digital M's have Sonnar formula lenses on them right now.
Yes...I was once recently tempted to purchase a used CV 50 1.5 Nokton. In the same price range used or perhaps a bit less expensive than a J3plus....but big . Alternatively, I thought a CZ post war Sonnar could be OK, but not a moderrn one, although modern are 200 bucks off at BH.
I think most people read the newspaper clippings and saw that the J3 plus getting love from all the right places. It could have been panned coming from Lomography and all , but didn't. Once the folks saw it was not the crapshoot buying a vintage lens from the Ukraine is, they got comfortable.
The front element definitely has a light purple coating. I can't tell if the rear group is coated. There is a yellowish tinge on the rear element that I don't see on the front elements. There might be a little purple, but maybe a reflection from other elements.
The attached photos look somewhat different than by checking by eye.