Purchased 3 Dell Precision M6400 laptops. These are the best of the best and all three suffered from the same issues .. lockups, stuttering sound and freezing requiring reboots. After contacting Dell I was passed off to 7 people (SEVEN) and the final person tried to pass me off to the original department. These laptops are $6000 but they have a serious engineering flaw that not even Dell will admit at least in public. Dell refused to even acknowledge the issue until I pointed them at numerous google hits for the same issue. Still fighting with Dell on this ! If you are tempted to buy a Dell Precision M6400 or M6400 Covet, RUN! read full review »