"As soon as you get into software-land, you wind up with these asterisks. And the asterisks say things like 'assuming that you've got something that is at least as good as what we told you to get, and assuming you aren't doing something stupid with it ...' There's a lot of conditionals in there," Day said.

In the end, of course, the dominant model going forward will be the one that customers are most comfortable with. Those most familiar with the advantages and disadvantages of the hardware and software models will be the ones best-equipped to make the right choice.

Email Jon Gold at jgold@nww.com and follow him on Twitter at @NWWJonGold.

in Network World's LAN & WAN section.