Drobo FS vs Drobo S (and using the S on linux)

I’ve posted this on the S forum, but for people that don’t go over there i’m posting here too, [color=#FF0000]please reply there[/color] to keep everything together

I currently have a drobo FS, and am thinking about replacing it with a drobo S.

on the fs I’m getting about 26MB/s reads and 35MB/s writes, the few numbers i’ve seen for the S seem to at least double those numbers.

this will be attaching to a linux server (ubuntu 10.04) using esata, any pitfalls i should be aware of?

on one page, they talk about LUN (logical unit) size, but it looks as if i can make one of up to 8TB instead of having to split it up, currently have 5@2TB (7.22 capacity by dashboard), so i should be able to make 1 drive?

i understand the difference in the filesystems available, but disregarding the different formats, this will just show up on any computer i plug it into as an external drive, same as plugging in a regular external USB drive?