- possibility to edit (extend, change) other people's posts. Comments are available, but less visible and not suitable for e.g. typo's in the original post
- ease of editing. Typing HTML codes is more work than wiki markup
- not possible to see how some things (including pictures, making lists etc.) are done because you do not get to see the source of other people's messages
- no list of recent changes
Advantages are obviously that we have a nicer link to the site and that we do not need to run our own server. Also, the user interface for blogger is localized and gets improved by Google over time.