For me it was the value. For what I bought: 2008 Vantage in White 6spd with 9500 miles, I would have had to pay $100,000 in early 2011 for that combo in a 911 Turbo. I drove a few Turbos, and it is stupid fast, great drive, interior is nice for what it is, and the smallness didn't bother me at 5'8- 180lbs. But the car just doesn't demand the type of respect/class that the Aston does. As far as drivability, I do not want to drive my weekend toy hard, and the 911 turbo is sort of pointless is you aren't driving it hard.

Driving down the street in and Aston Martin is an experience, driving the 911turbo would be for personally enjoyment.

Would I get a 911TT? Absolutely, but would need some exterior mods to bring the look up to par with what I expect from a car now.

 

For me it was no contest. I drove the new generation porche. It had a cool liquid display dash, would turn off at stops, updated interior and it was the s model. But I wasnt interested in micro seconds lap times, 0-60 times or any other performance numbers.
I purchased mine off the dealer showroom. I wanted black with no mettalic, paddle shifters (my m6 is manual). red calipers and black interior. They had my exact car there!
After looking, sitting in it (didnt even drive it) I couldnt shut up about it for hours with my wife! (think she got jealous...)Its just a unique piece of rolling art. The way you sit low, the rumble/vibration from the exhaust, looking at the rear quarters out the side mirrors. I can go on and on.
As I believe Dr G said "just go drive one"

 

I was driving a Boxster S right before I switched to the Vantage. It's hard to fault Porsche, except for the ubiquity of them.

To be honest, I find the 997 cars to be from the same school as the Vantage. Plenty of feedback in the steering, lots of fear noise, linear handling. More similar than say driving a GTR or R8.

The experience of driving the Aston is in another league. The beauty is obvious, but it's all the little things like the hinge for the tiny visors, that reminds you, this is not a mass produced car.

It connects in your soul. I honestly think performance is easier than character. Both the Aston and Porsche have it. But the Aston is exclusive. .

 

I first started thinking Aston when I was looking for a big front engined GT and saw a DB7 for sale in (what I thought at the time was) my price range. But all the Ford interior bits in that car turned me off. Despite all the carbon fibre etc, I knew that the little red/blue Ford Focus climate control dials would drive me crazy long term. Then I saw the Vantage and somehow my price range seemed to migrate in a hurry . Aston did so much right with this car ... (and I would add that the only thing that bugged me about the 1-77 was seeing all the familiar current interior elements in there ... you would think they could have created some new ones for such an exclusive machine ... but I digress).

I like the 911, I respect the 911, but I've never loved the 911 ... as for Astons, I won't reiterate what's been said already in the other comments in this thread ... I think they sum it up rather nicely.

 

Okay I'll play devils advocate... I would never replace my GT2 or even GT3 for an Aston.... To me it's not a fair comparison. They are totally 2 diffent cars, Porsche is a sports car which is super connected to the driver, it's a fine mechanical performance scalpel of a car, corner carving visceral speed machine... Aston is a classy stylish exotic hand built w limited quantity and very special crafted automobile...exudes exclusiveness and uses bespoked fine materials and attention to detail, like a custom hand tailored suit from London. Totally two different experiences, I think the Aston rather than comparing to the Porsche, makes a perfect stable mate... The cars complement each other, not compete or compare to each other.... Just my opinion

 

I'm nearly equally fond of Porsche's. The Porsche dealership here in Vegas suck bad. Most horrible experience ever. I like to change cars yearly and might opt for a Porsche next year but it will be from another state.

I also like the exclusivity of the Astons.

 

You can't compare the AMV8S and the 911 GTS.

The AMV8S gives you something the Porsche will never give you, at any level of modification.... it is EXCLUSIVITY!!! The car is a GT that has a certain allure and legend to it. People think it cost a lot more than it really cost. They think it can do things it can't really do. They ask you if it is faster than a Ferrari, it isn't. But it is that exclusivity, legend, and fantasy, that after a week of driving the car you will understand;... you are not one of the bunch anymore, but one of the few!

The Porsche 911 is an instrument of precision. It is for the driver that puts feedback and clear communication of the car's behavior,from every part of the car that touches him or her, above everything else. It is for people that draw pleasure from driving.

Let me ask you a question, which one would you buy? A Rolls Royce Ghost or a BMW 760iL???
If your answer is the Royce.... buy the Aston !!!!