My findings on a similar system are the same. I never could get QuickSync quality to work. I also found no speed advantage of using QuickSync Speed over CPU only. Here is a link to a previous post of mine with some of the numbers http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=872603 Given the possible "quality" hits with GPU acceleration for rendering that have been discussed in other threads, the prudent thing is probably to stay with CPU only rendering.
Thank you for contacting Sony Creative Software. The Intel Quick Sync Quality hang issue is known to development and they are looking into it for a future update of the software. At this time, it is recommended that you use the Speed option, or just CPU only. You will not see any quality issues if you choose one of those options.
If you still have a follow-up question on this particular incident, please feel free to update it. If you have a completely different question, please create a new incident.
Sony Creative Software Inc