The tactical situation and strategic situation has no possible comparison with Stalingrad
If you look at the map, US forces, along with Britain, will go north on the left bank of the Euphrates and the right bank of the Tigris.
So, Baghdad will be attacked from the east and the west, While Stalingrad was attacked from one side only.
The control of the air is from the US. Iraq lost control of the sky back in 1991.
The US has access to endless supplies, the Iraqi supplies will be limited in time.
Of course there are the bad points.
While the combat goes to a city, you basically have a lot of difficulty in using tanks. Tanks are useless in a city and are easy targets without the proper infantry support.
But if the US uses it's infantry to support it's tanks, then, they will loose much of their capacity to use their overwhelming air superiority. I would suspect that the best anti aircraft missiles Iraq may have will be at Baghdad. This means that they could considerably reduce the US air power.
In the end the result is inevitable.
The BIG problem, is that if things go bad, if Iraqis do not surrender, the only way the US has to reach it's objectives are:
1 - Stop at the gates of Baghdad and wait till the city surrenders by starvation.
2 - The US uses carpet bombing tactics.
In each situation the political image of the United States will be dreadful.
Democratically elected governments that helped the US will not stand.
Middle east governments will be forced to act in some way, even if symbolic against the US.
The US will be in a political mess, from where it will take ages to get out.
In the end the disadvantages to the US will probably top the advantages of going to war in the first place.