upgrade program - why would i need a dealer code?

[AnKran]

Dear Guys,

i recently started the upgrade process form expert 220 pro to CI. it was still free of cost on my account and i hope it will  be picked up soon.

My question is:

- What will be exchanged or added during this upgrade
- What stays as it is
- is there any new warranty start to run after this??
- is the sound imporvement really noticeably?

Maybe some have experince already and can explain a little more in detail

Thanks a lot..
Andy