Just thought I'd mention that I am using *very* cheap cables in my (non-3D) HT without issues. The last lot I bought was 2x 1m HDMI cables for �6.99 delivered in 2008.
I think that the fact that *every* HDMI device in my HT is connected to my Lumagen Radiance makes a big difference.
Why?
Well, reading the Lumagen support forums, it's clear that although HDMI cables carry digital data, the HDMI interface specification is too loose and difference in voltages at either end of the cable can cause problems. If both ends of the HDMI connection are at the opposite and extreme end of the voltage specification, things just don't work. I think it's likely that the Radiance (which is designed to work with everything and is extremely well engineered) is an excellent buffering hub.
Excellent point, many 'faulty' cables would I am sure work in the configuration you have, I have an Octava HDMI switch and it does not boost anything it just ensures all signal voltages are exactly right (well that is what the documentation says!), also have an HD621 and I trust that does the same? never had a cable failure, interested to hear others experiences?
I run similar sources but used the HD621 to strip audio first in the chain and pass video to the Radiance. The HDMI cables are relatively inexpensive Bluejeans BJC-2(I wanted custom lengths). No issues but I don't use 3D but the mandatory 3D formats don't require any greater bandwidth than 1080p/60.