I've had my 330cic ten years now and still love it. It is much "tighter" then the e30 it replaced and has held up well, although it has lived a charmed life and only has 50k miles.
Drawbacks compared to a hard top version are:
- More wind noise than a hard top when the top is up.
- people with legs don't like to be in the back seat.
- Can't fold down the backseat which limits cargo carrying duties
I would highly recommend the wind blocker. Huge difference with it on / off and how much top down freeway driving you can stand.
On the squeaks and rattles, mine does not have any. I had one squeak when the car was under warranty, went to dealer, came back with the same squeak. I spent 30 minutes messing around with the back seat cushion and the squeak was gone and has not come back.
It's a great ride and the prices have really come down.