Sadly, we've had more stability issues with Tiger than Vista within our organization. While the problems in vista seem to be more driver availability and some incompatabilities with older software, with Tiger, we've had all kinds of weird issues with finder content not refreshing, printing not working at all (to any printer) until reboot..etc. Just weird things that seem silly in this day and age.
We even had two machines side by side looking at the computers on the network and one would see machine called "X" lets say and the other would not show it in the list. No matter what we did it wouldnt show. Even upon reboot it failed to show. Very weird. Both were running 10.4.x at the time. It was a 2K3 server that failed to show but other 2k3 servers we had still were there.
Anyway from my experience in our environment where we have 100+ XP stations, 10-15 Vista stations and 20 OSX stations (10.4) I can honestly say that Apple is grasping at straws with the ads. You may not like the UI but all the talk about stability and viruses and all that being a major issue is a farse. In the 4 years of being at the company, I have yet to see 1 comprimised computer (Virus, Trojan or Malware). All the ads are doing is annoying the people who are computer literate enough to use both platforms and the ones that fine them believable are the inexperienced and gullable. Thats my take on things. Even speaking to the hard core designers who have used both platforms, they find the ads unprofessional.
If you've ever seen a really small cocky guy being all loud mouth and pushy even towards the big guy... Well you know where I might be going with this. I believe in speak softly and carry a big stick. The ads IMO show apple as the 'little' guy who makes a lot of noise. One day he's gonna get hit. LOL.
Really, with MS office being such an important software for a lot of people, all MS would have to do is stop development of that product on the apple platform and it would do major damage. Not sure if anyone else feels this way but I think its retarded to poke the sleeping bull with a big stick....