I do agree with most of your comments.

I feel the styling of the unit looks cheap, but internally it is well constructed with a strong chassis. Pity you had trouble with the first one.

Testing the TiVo's built in signal meter against an industry one, the TiVo is actually quite accurate. My Samsung show a signal level of only 42, while the TiVo is on 80.

What levels do you get with the replacement unit? If much over 80 you may actually have too strong a signal flooding the tuner. But yes the TiVo's tuners are not as selective as most cheap STB's. Hopefully this is just a software issue as DVB-T is new to them.

What setting do you use for Dobly Digital? Some people have reported fluctuating audio issues, and have changed to PCM as I have posted about earlier. this is only temporary fix until HTS sort out the problem.

Personally I don't have any sound issues other than the ABC news, which is an ABC issue.