So just got back for the dealer. The car I drove was a 2006 v8 vantage with around 30k on the clock, Titinaium silver with the upgraded stereo, up for £39k.
Interior: it's nice inside but the central switch pack really let's it down and shows up the cars age and looks a bit plasticky, I have to say that I think the interior of my Z looks more modern. Perhaps it's almost an advantage the Z being so barren inside that there isn't anything to look old. However the driver instrument panel in the Aston is very special indeed. The seats are very comfortable and supportive and the seating position is actually similar to the Z, however the cabin feels much more spacious. Due to the rake of the screen the bonnet feels a long way away.
Driving: The steering is very direct, more so than my Z and it felt really planted on the twisties. It seemed to have quite a quick rack, you could have a lot of fun on proper driving roads. The brakes were also very positive and firm which felt very good. The clutch was very heavy and the bite point very high, not sure if this was due to clutch wear (the dealer assured me not), but it certainly took a bit of concentration to pull away smoothly.
I also struggled a bit with the accelerator, if felt quite unresponsive for the first 15-20 prcnt of travel. I like to heel-toe when decelerating but the revs just wouldn't blip. Maybe it's the sort of thing that one would adjust to in time, but the Z certainly has better response in that area. That said, once passed this dead spot it felt much better.
Acceleration, whilst I didn't give it everything (it was wet and I saw an unmarked police car on the way to the dealers), yes it felt rapid.
It was also very refined whilst tootling around, a lot quieter than I was expecting, which I was a little disappointed in, I would have preffered to be able to hear the v8 rumbling away, HOWEVER, we went though a tunnel with the windows open and gunned it and I am not ashamed to admit a bit of s£x wee came out, wow it sounded truly amazing!! It would be worth paying the money just for the sound!
So I'm not sure how I feel about it at the moment, it truly is a beautiful car to look at and when pushing on it sounds fab. It handles very well, but I think I need to drive a couple others to understand whether the clutch and accelerator behaviour is normal. The controls all feel a bit outdated but other aspects of the interior are really nice.
Finally the dealer offerer £9.5k in part ex for mine.......
so I suspect, when the day comes to move on from my middle aged need for a roadster, the DB9 will be very high on the list of replacements. 
