I never get taken seriously at any vaguely upscale dealership. 
Maybe you should take one of us with you. 
Managed to test drive an S40 T5.
The rumors of good Volvo seats are true. 
The T5 engine is also very nice, pulls neatly even in 5th gear, and sounds great. Interior wasn't bad, but I feel the materials were slightly below that of the TSX. More rattle-y though.
The center LCD screen is a real letdown given the genius of the rest of the center console. 
Glad you got a test-drive. Anyone driving a TSX should have no trouble getting seat time in an S40, which certainly is no more upscale.
Did you test-drive the auto or the manual?
Anyway, I agree about the interior. It's very Ikea-like, which is to say that it's charming and Swedish but not particularly luxurious. It's MUCH better in light colors than dark, though.
By the way, I think that the C30 offers far better value than the S40 (at least with US pricing), and better looks. Tests I've read suggest it offers significantly more body rigidity too, while still offering a lot of utility if you don't demand four doors.