Another possibility is Timbuktu. (Or PC Anywhere if you are Windows-PC only, or VNC).
Run one computer “headless”. Using Timbuktu, connect to it from the other computer whenever you wish to access it. You can leave the Timbuktu window running but in the background / minimized while you work on the main computer, then switch to it and maximize the TB2 window to take up full screen.
Unlike a KVM switch, you can use this to run not only two computers from a single monitor/keyboard/mouse, but a dozen or more.
(If you’ve got Linux boxes in the works, there is unfortunately no Linux TB2 client, but you can always ssh and export the video back to your current screen, which accomplishes the same thing)
The main difference between a DVI connection and an analog VGA connection when hooked to digital LCD screen is that the inherent loss of precision that results from the analog VGA signal being converted to a digital display will be eliminated. If you are able to look very closely at an LCD screen displaying an analog signal there is often a very slight shimmering “crawliness” or jitter to fine detail features. With a direct digital input this conversion interference/loss is largely eliminated and the overall picture seems more sharp and stable to the discerning viewer.
This is why display screens on the better notebooks often seem more sharp and precise than destop PCs hooked to LCD monitors as the connection is direct digital video signal to digital screen.
By using a direct digital signal from the Radeon you are getting this same (or higher) level of quality for your large LCD monitor. With a good monitor and card combo even the small detail features are nearly pin perfect optically to the resolution limits of the LCD screen. This improvement would be most noticable in CAD and office apps like word processing where lots of tiny static elements are being displayed. Gaming and motion video playback will probably not show much improvement from the direct digital aspect, although the Radeon card you are getting kicks serious ass in all departments so there may be some improvements over your previous card in these aspects as well.