There are a few more differences but they aren't as significant as the winglets, more along the lines of different door seals, light lenses, "hub caps," etc. I, sure here is more but my train by memo on the differences was over a year ago and I don't fly it anymore...

From reading the article. It looks like emb did the winglet flight testing for cruise flight and didn't do an fms and dispatch performance change for takeoff. Perhaps the 1000nm is an 8000' msl takeoff or approach climb limit and the fms and dispatch mod will get second segment and app climb limit weights higher.. enough to get fuel for an extra 500 nm.

United needs a 100 seat jet and the 65 100 seat order number alone with the 253
70/76 and 50 of the 50 seater plan to only stay pass 2020 will cover 42% of the Express seat available they have today