by , 11:35 AM EDT, October 25th, 2007

Mac OS X 10.5 isn't due out until Friday, but The Wall Street Journal's Walt Mossberg has already offered his first impressions on Apple's latest operating system. It may be an evolutionary step up instead of revolutionary, but it still outshines Microsoft's Windows Vista.

"I've been testing Leopard, and while it is an evolutionary, not a revolutionary, release, I believe it builds on Apple's quality advantage over Windows," Mr. Mossberg said. "In my view, Leopard is better and faster than Vista, with a set of new features that make Macs even easier to use."

Time Machine and Boot Camp top his favorite feature list. Time Machine is Leopard's automatic file backup system that lets users "go back in time" to find older versions of their files or recover deleted documents. Time Machine also supports Leopard's new Cover Flow and Quick Look features -- both useful for quick file browsing.

Boot Camp is Apple's tool that lets users choose to boot their Mac with Mac OS X or Windows. This feature gives Apple another leg up on Microsoft since it helps Windows converts feel more comfortable as they transition into Mac OS X.

Installation went relatively quick and smooth, and took less than an hour. Once installed, there weren't any issues running applications including Microsoft Office, Firefox, VMWare Fusion, and Adobe Reader.

"In fact, every piece of software and hardware I tried on two Leopard-equipped Macs -- a loaned laptop from Apple and my own upgraded iMac -- worked fine, exhibiting none of the compatibility problems that continue to plague Vista," he said.

On the down side, Mr. Mossberg found the new translucent menu bar difficult to use with dark desktop images, and icons appeared to be duller and flatter than Mac OS X 10.4 or Windows Vista. Also, network-based destinations for Time Machine backups must also be running Leopard, and in some instances Safari rendered fonts incorrectly.

Startup times, however, were very quick. Mac OS X 10.5 took 38 seconds to go from shut off to fully booted and connected to the network. In comparison, a Windows Vista machine took almost two minutes.

While Mac OS X 10.5 may not be the revolutionary upgrade many have been hoping for, Mr. Mossberg sees it as a strong step forward, and a powerful tool to help sway Windows users over to the Mac camp.