I bought a brand new e60 520D a few years ago and soon regretted it. Mark summed it up perfectly, once you are used to more power you won't want to settle for less. I ended up changing it in for a e92 335D (and remapped it)
The 330D is in a lot lower insurance group than the CLS350CDI I've just got rid, will use less fuel and cost less to tax so I'm happy.