I have a PC with a 24" monitor right next to a Mac Pro with a 24" monitor; I share a keyboard and mouse using Synergy.<p>I'm going to be moving to Mac only pretty soon and plan on upgrading to a single 30" monitor.<p>2x24 is nice, but there ends up being a lot of side-to-side head motion which gets tiring after a few days; and the most premium screen real estate (straight in the middle) is taken up by the bezels of the monitors.