Technical specs are great if you're selling to engineers. But for business folks, it's all about ROI. Point out that you get the functionality of a PDA + the most commonly used functionality of a laptop at a cost far less than the two combined and your mobility goes way up (how many people haul their laptops to every meeting? Not many - it's too painful). Plus your software cost is virtually zero and your IT maintenance cost is also next to nothing (spyware? anti-virus software? 100MB service packs? not necessary on the Zaurus).
How about the cost benefit of the improved security of Linux? Not much chance of a Zaurus that's been "out in the wild" coming back home, plugging into the WLAN, and trying to infect the whole corporate network with the latest Windows worm that you picked up from the WLAN at the airport because you've been on the road for a week and missed a critical security update. Can't say the same about a Windows laptop How much more expensive is that Windows laptop when you factor in the cost of your whole IT departement working through the weekend to clean up and patch the machines that got infected when the infected laptop came home?
How about the reduced cost of custom software development? Creating a non-trivial buisness app for PocketPCs is very labor intensive. With the Zaurus you have the power of Open Source behind you and you can leverage far richer software libraries and more efficient app development tools like Python. With Python or Java you can even have some portability with the same app able to run on the Zaurus, Macs, and Windows PCs. Yeah, you can port from PocketPC to Windows and vice versa but you gotta plan for it up front and really know what you're doing (or have a big development budget). .NET will improve this someday, but the Zaurus can give you app portability now.
Now if Sharp had just hired me to consult on their Zaurus marketing strategy ...