I like it mainly because the fonts look better, staring at computers all day and having to look at ragged text is not good, but iTerm does much more:
This is from iTerm web site
http://iterm.sourceforge.net
"iTerm is a full featured terminal emulation program written for OS X using Cocoa. We are aiming at providing users with best command line experience under OS X. The letter i represents a native Apple look and feel of the program interface, and an emphasis on complete international support. iTerm was merged from two projects, CTerminal and TerminalX, both of which were based on JTerminal project. The current version is still in beta stage. It is however very much functional and usable."
Scripting support:
"iTerm has sophisticated Applescript support allowing one to write stand-alone scripts to launch the application and open multiple sessions from the addressbook into either new tabs or new windows. You can also set some other parameters for a session such as foreground and background colors, and transparency. Here is a sample script"
Later
Joe