If you are a fairly involved photographer and printer, you could benefit from the Worksheet module that the Pro version has that the 2.3 version does not. The Worksheet lets you lay out your entire workflow and see your image change from profile to profile. If you do your own prints, and do your own profiles - it really helps to have a good diagnostic program like this to troubleshoot when problems arise. (Sometimes you don't realize you need it until your color's off and you can't figure out why.) The 3D grapher also looks nicer and has more options in the Pro version compared to the basic. You can
take a look through the manual to get an idea of what it does.
That being said, the basic (version 2.3) does a great job of showing monitor & printer gamuts along with your image gamuts. You can also see how different rendering intents affect the image pixels. It will also draw directional
lines showing the color moving from one color space to the one represented by your profile and rendering intent.
In my decidedly biased opinion the grapher in both versions is more accurate than anything else on the market, since Lab space is 255 wide by 100 tall: (
Read Color Management Myth #26)
And if you're on Windows we have a brand new version that is updated for Windows 7
