Its funny but LG together with Samsung are among the few companies that manufacture ATSC tuners , not only that, they are part of the ATSC task force that develops the standard and related technology.

Sue the question is , Were both TV connected to the same coaxial cable for a proper comparison?, or Did they have their different feed line?. It maight have been that the coaxial for the LG was longer or in other words with more losses along the line.

In any case , yes , not all tuners are creted equally, some have better sensitivity therefore perform better than others. i rather choose a TV set for its display performance rather than its tuner sensitivity , the latter can be overcome with the proper antenna system.