What was your previous setup ?
There were two relevant prior setups. One was a pair of B&W 705s with a Purifi-based amp and a graphic EQ used to roughly dial in room EQ (and dial out the 705s' treble peak). The other was a pair of Infinity Kappa 9s with the same Purifi amp and with a MiniDSP SHD doing room correction through Dirac.
Both of these setups produced a strong, clear phantom center. I found the Kappas much fiddlier to deal with and so in some configurations I'd say their center was not quite as strong as the 705s, while in other configurations it was equally strong, and in other configurations it was a little stronger. But in general it was strong and clear.
The Kappas produced noticeably better soundstage depth than the 705s. And of course more and better bass: 2x 12" woofers per speaker doing only bass frequencies vs 1x 6.5" ported midwoofer going all the way up past 2kHz on the 705s. I was amazed at how much bass the 705s could put out given what they had to work with - although when listening to the Kappas and now with the Genelecs I realize how much of the 705's bass beefiness was just low-order harmonic distortion.
The Kappas also produced notably taller soundstage height than the 705s: They're 5 feet tall and the baffles lean back slightly, meaning that all the drivers that cover the directional frequencies are either mounted above seated listening height, or have an acoustic center that's above listening height by the time it reaches your chair (because the leaning baffle tilts the drivers up slightly).
As for soundstage width, for the most part I surprisingly found both speakers to be similar, with the perceived L-R image rarely seeming to extend beyond the outer edge of the speaker.
In my perception, the Genelecs produce a noticeably sharper, tighter phantom center; wider soundstage; deeper soundstage than the 705s and more consistent soundstage depth than the Kappas; far more, cleaner, and more linear bass than the 705s; different but equally good bass to the Kappas; and nearly as good soundstage height as the Kappas.