That was my first thought as well, but after playing around with it all afternoon, I'd say that I'm "cautiously optimistic". It's quite snappy, and they clearly put a lot of thought into optimizing what it shows and when. It would have been super-helpful when I was first getting started with MMA, and as an experienced user I'm finding myself using it more than I would have expected.
My one gripe thus far is that there isn't as much keyboard control over the prediction interface as I'd like, but that could just be that I haven't found the shortcuts yet.
One thing I quite like about it is that there's a built-in "feedback" feature- any time the "predictive UI bar" is showing, there's a button you can press to send semi-structured feedback about what's currently showing, suggest other things you'd like to appear in similar situations, and so on. I've used it already to suggest a few changes the prediction UI for ListPlot.
My one gripe thus far is that there isn't as much keyboard control over the prediction interface as I'd like, but that could just be that I haven't found the shortcuts yet.
One thing I quite like about it is that there's a built-in "feedback" feature- any time the "predictive UI bar" is showing, there's a button you can press to send semi-structured feedback about what's currently showing, suggest other things you'd like to appear in similar situations, and so on. I've used it already to suggest a few changes the prediction UI for ListPlot.