[SD987]

Pros:

You'll get a car that is the first year of the model run, instead of the last and presumably most "solid" of the previous run. I don't think this is too much of an issue in that despite 80% of the 987 being new, the engines have basically been carried forward from the 986 although tweaked.

Basically double your warranty.

The 987 looks better, and is generally the superior car

Cons:

You'll be going from a manual (I assume) to a tiptronic 987 S, which will actually be slower than a 987 base and slower than your 2003 S. But then again, I'm not familiar with rush-hour traffic in Warsaw.

Doesn't seem to make much financial sense.