“The fifth major update to Mac OS X, Leopard, contains such a mountain of features — more than 300 by Apple’s count — that it’s difficult to boil this US$129 operating system release down to a few easy bullet points. Leopard is, at once, a major alteration to the Mac interface, a sweeping update to numerous included productivity programs, a serious attempt to improve Mac OS security, and a vast collection of tweaks and fixes scattered throughout every nook and cranny of the operating system,” Jason Snell reports for IT Business.

“As with every OS X update since version 10.1, there’s no single feature in Leopard that will force Mac users to upgrade immediately. Instead, it’s the sheer deluge of new features that’s likely to persuade most active Mac users to upgrade, especially since this is the longest gap between OS X upgrades — two and a half years — since the [operating system] was introduced,” Snell reports.

“It’s impossible to detail the avalanche of new features in Leopard. Screen Savers and international spelling dictionaries aside, Apple’s list of ‘300+ new features’ isn’t far off. If you use Photo Booth, Parental Controls, Image Capture, VPN, Terminal, or just about any other feature you can think of in Mac OS X, you’ll find at least some changes,” Snell reports.

“So are 300-plus new features worth $129? That answer will vary, because no single user will ever take advantage of all — or maybe even half — of those 300 features. But given the impressive value of Time Machine and improvements to existing programs such as iCal, iChat, Mail, and the Finder, most active Mac users will find more than enough reasons to consider that upgrade cost money well spent. Despite a few interface missteps, particularly when it comes the menu bar and the Dock, Leopard is an upgrade that roars,” Snell reports.

Full review, including how many of Leopard’s new features specifically address security concerns, here.