Have you been told that HDMI is the ants pants and bees knees? That it's the modern solution for the digital revolution and therefore always better than analogue? If so it might come as a shock to hear that it's not actually perfect, but a flawed format that's been enthusiastically adopted without really thinking things through.
HDMI was designed to benefit content providers first and foremost. It's all about copy protection - making it difficult if not impossible to pirate HD content. Of course, in order to gain popularity, something new had to be offered, so the appeal comes from using one cable for both audio and video. Sadly, it's a poor format that falls short in a number of areas.
Problems with HDMI
The biggest problem with HDMI is that it is not suitable for the kind of runs that will often be required in a home theatre. About 5 - 7m is the limit and beyond that you can expect problems with reliability. HDMI uses twisted pairs rather than coax which is the much more sensible choice. Coax cable can be run over much longer lenghts without any problems and is much easier to install.
Blue Jeans Cable explain the problems in more detail >
The future is HDbaseT - read about this new format that is far more promising more >