The official CDSpeed scan speed for newer Liteons is 8X. I, and others, have found that this speed is not consistent for many drives and that there are variations within models. I stick with 4X as I have found that it is much more reliable. The only benefit to faster scanning is that it is faster. If you do some testing for your drive, you will be able to see if your drive is OK at 8X, just compare it to 4X.
If you post here at 8X, no one should call you on it. If you post at 4X, some will. If you post at 16X, many will ask you to change.
Scanning is for Liteon burners, not ROM drives and some people have reported problems with the 18X and 20X Liteons for scanning.