TrueHD & DTS-HD MA sounds the same whether the player decodes it or the AVR decodes it. In this case, it is basically like a .zip file, which makes it very different from the older codecs.
TrueHD & DTS-HD MA are lossless compressed, when decompressed, they make LPCM streams. It does not matter what decompresses them, the result is the same.
The debate then goes onto whether sending the compressed or the uncompressed has a better chance of corruption in the cabling between the player and the AVR (from EMI, etc).