My understanding as that the very first 45 versions I believe it was the shield 45 did not have the 2.0 envgraved in the slide. This was because of marketing. They wanted to bring the 45 shield to market. But they didnt want to pre-emt the full blown 2.0 marketing campaign until they had the full size and kther models to offer all at once.

So apparently S&W decided to NOT emboss the 45 shield with the 2.0 description on the slide. And waited to do that to correspond to the whole roll out of the 2.0 line.

From what I understand, the only difference is the slide engraving. All else was/is identical.

IF that is true, there may be some collector value for these 2.0 guns that are NOT engraved as there will only be a limited number of these guns compared to the full 2.0 production marked slides. But frankly I doubt it would add much if any value at all.