Phil (pscocoa) is your man, he owned one for donks.
I have had 6 years trouble free, 60,000 miles. Only servicing and tyres - not even changed brake pads - this will be needed this year. I have the 3 litre diesel and despite car weight and permanent 4wd it is very quick and returns 37mpg on a run.
However - if something does go wrong it will not be cheap - for example if change pads and discs all round this year - VW price will be £1200. If I go indie - probably still £600 ish.
Divide that by 6 years and maybe not too bad.
The drive is fantastic.
If the OP can find an indie that can work on these then worth a punt. However, the suspension on the 2003 is the old air strut system for which parts are not available - he should quiz seller carefully as to any fault codes showing and whether suspension is ok.