Microsoft delivers the goods at PDC 2008

LOS ANGELES--As developers began to get their hands on Windows 7 Tuesday, they offered varied reactions to the Microsoft operating system update.

Windows 7 arrived in various forms here at Microsoft's Professional Developers Conference. Windows VP Steven Sinofsky showed its key features on stage, the OS appeared on PCs throughout the convention center, and developers also got their own copies to take home with them.

Attendees to PDC 2008 received pre-beta copies of Windows 7 on DVD, as well as a 160GB Western Digital portable hard drive packed with code.

In addition to the Ultimate Edition of Windows 7 (Hint: it looks like Microsoft isn't planning to ax its notion of an ultra-high-end version of its OS), the hard drive also comes with, among other things:

•.NET Micro Framework development kit 3.0

•Azure Services Training Kit, a set of hands-on labs, presentations, and samples.

•Live Framework SDK, documentation, samples and tools to build on top of Microsoft's Live Services.

•Software Development Kit for Windows 7 and .NET Framework 3.5 Service Pack 1 (pre-beta)

•Microsoft Robotics Developer Studio 2008 Express Edition

•Visual Studio 2010 & .NET Framework 4.0 CTP

•Windows Azure software development kit

That said, there's still some room on that hard drive. Of the 149 GB of usable space on the drive, 91.8 GB are free.

During the keynote on Tuesday, all of the PCs scattered around the convention center for folks to check e-mail on were switched to Windows 7. Not everyone appeared to notice the change, though. One attendee, for example, said he didn't notice that it was Windows 7 until a reporter started taking pictures of the screen.

While attendees picked up the swag, others were trying out the new Windows 7 operating system in hands-on labs in the main hall of the event. The reviews were mixed.

"It needs some work as far as usability is concerned," Matthew Firth, chief technology officer of online pet pharmacy PetCareRX, said as he tried to move an image across a touch screen with his hand. "The controls could be more intuitive. I guess there's a learning curve associated with it. If they can get it right it could be just as revolutionary as the mouse was."

Falling touch-screen prices and the eventual adoption of Windows 7 will mean Firth will have to optimize his company's Web site for touch, he said.

In the meantime, Firth said he's thinking of getting a touch-screen monitor and Windows 7 for his kids to use at home. "They like to paint. It's less messy and my son won't eat the crayons," he said.

Allan Thraen, a software developer for Swedish content management firm EPIServer, said the touch capability was "totally cool" but complained that the operating system overall seemed "still a bit buggy; not totally smooth."

He and others also said that the Windows 7 user interface was too similar to Vista.

"It looks like a re-packaged Vista" with "a little bit of eye candy," said Daniel McGloin, a software engineer at Intuit.

Keeping the underlying code similar means fewer incompatibility issues with apps and drivers, but "is it compelling to the end user? I don't know," he said.

Other users saw Microsoft's decision to keep many things the same as a good thing. "This is what Vista should have been," was a refrain heard (and overheard) several times on Tuesday.

Not everything was about Windows 7, either. There were also a number of Microsoft's Surface machines, which is just now being opened to a broader range of developers.

In addition to a scavenger hunt sponsored by Microsoft, some third party developers were showing off applications written for the Surface multitouch interface. In this video clip, Meaghan McAllister, marketing coordinator for software development and design firm Identity mine, demonstrates the company's new an application written for Microsoft Surface that allows for the display of digital photos on multiple multitouch screens:

(Ina Fried of CNET News.com contributed to this report.)