Blimey this topic is going on a bit! in answer to the moles questions - as one who is currently looking to change to a Diesel and a 330CD M Sport Coupe to be precise.....
1. Don't know about more expensive I have seen some very good deals out there on the 330, and with no confirmation that the 220D will have an auto option, then Lexus kind of made the choice for me.
2. Yes I did, given the choice again (and I really do love my IS) I would buy a BMW simply due to the fact they retain their value more. I have lost an arm & a leg in the last 18 months.
Can I also add that in terms of performance the 330 is a bit of a beast!