The picture and audio from the ET unit was fine via HDMI, but the output through the composite jacks (top and bottom) was awful quality (e.g. when recording to HDD recorder). I can't comment on the optical out dropout issues etc. This combined with the unit freezing every couple of days when attempting to change a channel, and thus need to reboot, was enough for me to park the ET unit unused in a shelf (I'll use it if I need a 2nd unit for something).
Unless that freezing was fixed, I'd have no trust in the unit for use as a PVR - even if the software did miraculously turn up!