Nothing at all.
I think the Taurus often times gets a bad rap. I am sure that some owners have had problems with their cars. I can honestly say that mine has been very good from day one. In 2001 I rented a Taurus SES (mine is the SEL with the Duratec engine) and I really liked the comfortable ride, it is a big car without being overly big. I decided to buy one in 2002 when I paid off my other car (Escort). I decided on the SEL Premium because it had so many options (puddle lamps, lol) and I wanted to try the Duratec engine which was rated at 45+ horsepower than the vulcan engine. Relatives who happen to drive much more luxurious cars than me complimented me on the ride and overall look of the car.
This car in my opinion has plenty of "get up and go" and is very safe. I opted for the traction control (safety package) which has been quite handy on a few occasions during snowy weather. I have three kids so safety is important as well and, it had high safety ratings. The only drawback is the resale value on this car. I intend to keep this car for a very long time so, resale value is not much of a concern to me. This is the first car that I have owned in which I catch myself inadvertently going 80 mph on the highway (when I am alone) ; it is that comfortable in my opinion. Also, I believe that the Taurus is no longer available as a new model for 2006 (fleet and rental sales only) so, a real bargain can be had by getting a used one. If you do consider one, I would recommend the Duratec over the Vulcan engine. That of course, is just my opinion.
The 200hp Duratec V6 is far better than the 155hp Vulcan V6. It also revs higher and has a better exhaust note.
I love my 2002 Taurus SEL Premium as well!