Hmm. In previous threads I've expressed my satisfaction with recent KDE releases - the whole series from 4.0* to 4.9 was a continuous improvement to me (with my use-cases on my systems - it seems some people had less luck), and especially 4.6 - 4.9 were incredibly polished/stable/feature-complete.
I can't say I'm anywhere near as impressed with 4.10; there've been seemingly idiotic regressions in some areas, especially the QML-rewritten plasmoids...why bother releasing your remade versions if they have (literally) less than half the features in some cases, and break almost every use-case I could actually thing of? The new screenlocking feature doesn't actually lock the screen properly, the power-management doesn't work, plasma-desktop crashes occasionally (never in 4.8/9).
At least Nepomuk is better, some of the applications have considerable improvements and they fixed the ugly background to the various settings/help windows.
It's still my DE of choice, and hopefully 4.10.x will tidy up bugs and a few feature-regressions, but it does seem to be a backward step overall. Which is a shame.
*Yes, yes, I know *anything* could be an improvement on 4.0...