I'm not sure what networking issues the Mac presents...its based on rock-solid Unix and Apple has always had solid workgroup/networking/autoconfiguration software initiatives built into its OSs. Appletalk? Bounjour? Their top-rated Airport WiFi routers (i.e. recent Consumer Reports, PCmag reports)? They've consistently been ahead of the PC curve in terms of reliability and next-gen initiatives (think their early system-wide pushes to Gig-E, WiFi, etc.). I worked in Mac-based computer labs in college that were the hubs of research, collaboration and document creation. The Mac was the preferred platform/host of the first popular mainstream web browsers (Mosaic etc) and streaming technology (Quicktime) and have always been at the forefront of media-rich networked experiences. Because they weren't dumb terminals w/ green phosphor text must mean they were 'toys' to some...to many of us they were always the machines we turned to to 'get stuff done.'
The problem in mixed networks are more often the PCs than the Macs...Windows file-name conventions, idiosyncracies w/ binhex keys, et al make the PCs a pain in the a** while the Macs more often config and work quickly and efficiently. I'm sure you network admins know this better than me--but I've worked in mixed platform environments for almost 2 decades and the Macs are by-and-large the least IT service-intensive machines in the company. Likewise, at home, my Macs are less troublesome than my XP PC in most areas, including networking.
Getting Windows files to Linux to Irix to Mac and visa versa is our mission here every day--and, in the end, its not Apples systems that cause the wrinkles, it's often non-standards based or glitchy software/file formats elsewhere in the works.
I look forward to putting Leopard through its paces over the next week--I'm sure it'll be as solid and trouble-free an upgrade as all the other OS releases have been (well, o.k., I had an issue w/ Panther and some old drivers on its initial release, but that was one bad experience in almost 20 yrs of Mac work).