I wish that our arts types would see it this way; unfortunately they are dyed in the wool Apple fanboys when it comes to such things, and also indoctrinate their students as such.
We use roaming profiles due to the amount of users who use more than one computer; having a generic or a local profile would cause a lot more problems than it would solve in terms of user generated data.
We also run gigabit ethernet with fibre backbones to minimise start up lag, it's only really an issue on the reletively small amount of Pentium 4 machines we have floating around.
We do have some issues with profiles not loading properly, but myself and the other helpdesk operators have the knowledge to reset profiles fairly easily.
You would cringe at the fact that we have profiles roaming between sites over the WAN links we have and DFS replication to every site (not for every user, but all group drives and users who travel a lot) LOL.
As for security, all user files are synced back to the servers on logoff, and for student users, their local profile data is erased automatically. We are in the preliminary stages of implementing drive encryption between all sites.