Unfortunately they confused Malkavian madness with plain idiocy, IMO. I mean, there are a whole lot of different kinds of mental illness but, I don't think any of them involves talking like a 16th century buffoon.
I'd much rather play a total paranoid or sociopath Malk. The fact that the ridiculous dialogue is actually forced on you (no apparently normal dialogue options whatsoever) doesn't help much, either.
The conversation with the stop sign was a nice touch, though. ^_^