You didn't mention the scale. Which will influence the build space needed.
If you can fit your models in the B9 build space, I would choose it because of minimum feature size. If it doesn't fit, you might not need the resolution anyway.
Speedwise the B9 gets more faster in relation to the Form the "fuller" a slice is, because the exposure time for a slice is independent of how "full" it is.

Sample of a tower interior in 1/300 scale printed on a B9

An Euro cent is a bit smaller than an US dime.

More images of the interior on
http://brumbaer.de/index.php/3d-printing/29-airport