I agree with your comments.
Not all ET's are alike. Some work better than others
Also other brand of HD Terrestrial box's dont seem to have problems with picture breakups or audio drop outs on optical outputs
My first ET box only showed about 5-10% signal stength. The second box shows about a 20% signal strength. If I inserted an attenuator in the aerial lead then ET reported a higher signal level. Other owners have reported similar effects with their ET's so signal level indicator seems to work backwards.
I am sure that there will be nothing wrong with your aerial or coax. I tried other another aerial and new RG6 coax with no change to the problems I have.
Like you I will just have to live with these problems with the hope that a future firmware update will fix all.
I am just using the RCA audio meantime and putting up with picture breakups.
Hopefully the immenent PVR functionality makes up for these issues.
Did you try the latest firmware? I dont notice any differences.
Peter - what issues did this address (other the green flash on TV3 which seem to have got fixed at the TV3 end)