I had a 156 JTD from new: I did 45,000 miles in it, and it never let me down. The entry level 8 valve 1.9JTD with only 115bhp, but loads of torque so point-to-point it was quite quick. Oh, and I averaged 49mpg....Great car.
As to unreliability, I'm not sure what engine you have, but I recall that the Fiat / Alfa 1.9 diesel is also fitted to Vauxhall / Opel and Saab diesel cars, and nobody seems to complain about those being intrinsically unreliable.
If you're allowing a reasonable budget for maintenance, you should have fun driving a very practical, stylish car.