In the past week or two I've noticed occasionally pausing in itunes. It could be from the green drives turning off (which I doubt since it hasnt happened until now), it could be from seeding linux distros off the same drive, ahem, or it could be from updating itunes. I have the buffer set high, but maybe something's going on with that. I havent spent much time looking into it, but I did finally set up my older Drobo, which I plan to offload the linux distros to, to free up resources and whatnot. I've not really had any problems until this, so I'm still happy with drobos thus far.
I'm pretty sure if you dont host linux distros on the same drive you'll be ok.