According to my experiences, there are no big differences in grammer and reading parts. But listening comprehension part in computer-based test is more difficult, since you can not read the questions before you hear the conversation or articles. You know when you read the questions in advance, you may catch some key words from there, which may be helpful to understand the conversation or articles.
+ J! k2 h2 P2 s- k) T9 WIn some part, people can not change their answer. but in some part, they can. there are some on-line practices for computer-based test which are very helpful.