2.2 has a major issue with oil path ways getting blocked, expect engine to seize or to have a problem with the chain.
CDTI - CIM module failure, expect £500 repair bill.

Stick with petrol as when it goes wrong you won't have a get a loan to fix it!
Matter of fact all vaux diesels are shite except the izusu 1.7td engine.

Personally I would avoid a vauxhall after 2000. They all have problems.
I wouldn't touch a tdci, only common rails I haven't heard about going wrong is the german stuff.
I tried to tell my mum not to get a 56 plate astra. 8 months later she had a £1700 bill.
She now doesn't trust it.