I am naturally sceptical about mods as I question why the manufacturer failed to include them if they make so much difference. Two questions here -
1. what exactly is the mod and what is the scientific basis of how it should effect sound quality? 2. How did you prove that the mod makes a real difference and does not introduce compromises somewhere?
If these mods really do make a differene then the manufacturers should be aware and news should certainly lead to better designed products.
My experience to date is that the benefits of latest technology nearly always the benefits of trying to 'bolt on' improvements to earlier ones. Just look at BD-Audio vs CD, for example - 256 times the quantisation resolution due to 24 bits rather than 16 - an undisputable improvement (if the speakers are up to the job of you hearing it).
Yes there are those that argue that analoge does not suffer quantisation problems but the end result in audio is nearly always overidden by the weakest link(s) in the audio chain, which are different for different media but an overwhleming influence is always the loudspeaker.