Whats the difference between Libre 1 and Libre 2 ?
As
@MeiChanski says, it's got a fairly primitive hypo/hyper alert system - choose your alert levels, it'll make a noise, but you then need to scan as per usual to see the number. It'll be useful for a lot of folks.
The other major difference is that v1 was "batch calibrated", which meant they made a batch of them, no idea how many in one go, then pulled a few of them from the batch, calibrated them against a known amount of glucose solution, then applied that calibration to every sensor in the batch.
Which would be fine if every sensor in the batch was identical, but they're not, which is why we get sketchy sensors.
With v2, though, they've said that they are going to be calibrating each one individually, not in batches, so that improves the chances of not getting sketchy sensors.