After looking at KDE 4 on a live CD it looks half like Vista and half like OSX to me. If you like it is a matter of taste (I don't), but configuring it is not straightforward to me.
The new start menu is clumsy and cumbersomely (click, click, scroll, click, scroll), and I found no way of configuring it. Even no way to add items. Moving to the traditional launcher would be the first thing to do--if I could (see below).
I found no way to add applications on the task bar as in 3.5. I found no way to move the pager as in 3.5, I found no way to change icon size there. Neither could I configure the font size of the digital clock.
Those items seem to be widgets one can add through this annoying yellow thing in the upper right corner. But maybe I'm to dumb, I can remove the widgets from the bar on the lower corner, but can't add them to it. Nor was I able to move, remove, resize or what else that bar.
And dolphin? I didn't like to use Konqueror as file manager, but dolphin doesn't look that great to me either. First of all it lacks a list view I was always using. And you can only split a view vertically, not horizontally.
All in all I've the impression KDE has been stripped down and the user has to like what the developers like and stick with that. I'm quite sad about that.
Robert