Common problems: dual mass flywheel, EGR and injector issues.
I had a turbo go on one ONCE [out of probably 30 or so dervs in the last 4-5 years] but thankfully the car was still under manufacturers warranty. Probably had half as many petrols and [touch wood] I've never had a problem that seems to be a common theme. The 2.0 v6 is dreadfully underpowered though imo.
Yes, they've basically mundane-ohs but [maybe it's in my head] they drive a lot better.
Cracking value for money now although I think they look best in light metallic blue!