If you can find a good one then they are great cars.
They rust in pretty much all of the places you can't see.
But check the inner front wings, inner sills, floorpan, especially below the rear footwells and also check below the spare wheel well.
Alfa didn't do a very good job of rust proofing them compared to most other Alfa models.
Also on the mechanical side make sure the engine has had regular cam belt changes (Every 36k or 3 years on the TS and JTS).
The engines tend to use oil. If run low they tend to have a habit of running the big ends.
The big ends can also fail if the cambelt has previously snapped and the shells were not changed.
Unfortunately neither the JTS or TS are very robust and neglect does have an effect. The problem is that running the car low on oil or not changing the shells can cause the big ends to fail a few thousand miles down the road...
Suspension bushes are also prone to failure, especially at the front.
Diesel and V6 cars are much more robust engine wise, but still not entirely bullet proof.
If you get a good looked after one it will be reliable, but these days they are becoming rare.