i was testing it early, much smoother than 1.4, lots of new features, but still buggy, cant compile maps, doesnt save settings unless u enable compatibility (for win7 probably vista too)
i tried 1.6 a while back, and my first realization (before reading anything) was that it felt a lot more like 1.4 than 1.5, which i thought most mappers would appreciate. i didnt use it that long though because i wasnt very interested in mapping, so i didnt notice any bugs. im sure theyll all be sorted out eventually though