It runs super fast now with the new x.63 build. Battery life is better but still kinda sucks. No major bugs, no issues, no lags.
Be aware, though, that you will lose Lumia Camera which is replaced by Microsoft Camera which is just a pile of garbage in comparison with the Lumia Camera. I seriously wonder whether it is worth losing it. I absolutely loved my phone for taking such amazing pictures, great video with stereo sound and much more, all of which is gone now on W10M. Feels kinda like a step forward followed by a bigger step backwards.