Older LWB Duetto versus newer MWB models

We've had a couple of the early LWB (cream) Duettos, most recently the Turbo, which was a better drive than the NA version) and are wondering whether to 'upgrade' to one of the post 2000 MWB models?

I imagine the later models are a more responsive drive, and full height doors would be nice (I bang my head so often!)
From other members' experience,
1) Are the later MWB models any more rust resistant?
2) Do they drive better? (I assume they all have a Tdi engine which delivers more power)
3) Apart from less storage, are there any other drawbacks to the MWB models?

Many thanks.