As I mentioned in the first post, I did have one build quality/QC issue with my first center. Well, two issues really.
First, the tweeter on the center seemed to have been screwed in too tightly. This caused the MDF and paint to crown. This was not an issue on the bookshelves nor was it an issue with the replacement center later sent to me.
Second, the fabric on the grill of the first center was not uniformly tight around the frame. This cause some blooming on the left of the grille. Again, this issue was not present on either of the bookshelves.
Both of these problems were only on the first center and did not affect the replacement center nor the bookshelves.
Speaking of the replacement, HTD's customer service is top notch. Chris at HTD upon hearing of the build quality issues of the center, quickly arranged to ship a replacement unit. He did this without first requiring me to send the bad unit back which saved on lead-time. I called him on the 22nd and the replacement unit was shipped the same day arriving at my home in California on the 30th. Just five true business days total; not bad.
If anyone has any questions about these or would like to request a photo of anything specific about them, please let me know.