I took the test last Dec. , scored 273 ( equal to about 643 on paper test ) with only 4 days preparation. My scores for the 3 sections were ,26 26 and 30, respectively.
The listening section is about the same with paper test, execpt that you can use your answering time freely by your self, which means you will have 10 or 15 minutes, I do not remember the exact amount of time, to answer all the question. I think that's a good thing to me. I only used a little more than half of that time limit.
The grammar section of the computer test is now combine with writing. If your writing is good, this is a good thing ( but my writing is bad, only score 5 ).
I think the reading section is much easier than paper test. Longer time with just serveral more quetions. You will have much time left. That's why I score 30, the highest score of the section.