IMO better components do not always result in audible difference as it depends on many factors. Before Dr. Rich called Marantz out on their use of cheap Op amp in the HDAM circuit of their then flagship prepro AV8801, there had been quite a few rave reviews including comparing it to the top Denon AVP and other more expensive prepros.
Then it became public, to the point Marantz had to defend their choice of those cheap OPAs (see below, quoted from
http://hometheaterhifi.com/reviews/receiver-processor/processors/marantz-av8801-11-2-surround-sound-processor-ssp/ ).
"Here is the response from Paul Belanger, Technical Product Manager for Marantz:
We use a discretely designed circuit in lieu of a standard Op-amp. The HDAM itself is sandwiched between 2 Op-amps in a diamond buffer configuration – the 8801 features 13 of these “discrete” HDAM boards – 1 for each channel. The HDAM SA2 is the circuitry sitting between the OP-Amps and is mainly defining the characteristic of the sound. The OP-Amps might not look best on the data sheet, however in this configuration with the HDAM and current feedback topology it was our choice for a good balance in sound.
Dr. Rich tends to focus very much on singular devices and the data sheets associated with them – Our design philosophy is quite different at Marantz. We use the appropriate component for the outcome and final sound quality we are trying to achieve. He may believe that the 8801 would sound no better than an entry level Yamaha via its preouts based on our choice of volume IC – but I can tell you in my experience, singular components do not make or break the final sound; from overall and surrounding circuit design, vibration resistance, materials to grounding points, there is SO much more involved in building a great sounding piece of audio gear.”
I can’t settle the fundamental debate on component parts between Dr. Rich and Marantz. What I can settle is that the overall goal of a product like the AV8801 is to allow the consumer to enjoy movies and music and it certainly does that very well. My reservations about the two channel audio performance of the AV8801 stem from the perspective that Marantz can do so much better. Marantz makes wonderful reference quality stereo gear and I was personally hoping that they would have included that reference level analog output in the AV8801. I also realize that doing so may have completely blown the price point for the product."
After that, one could start anticipating Marantz would do something about their HDAM modules, and sure enough they did something with the 8802. Question remains, is Dr. Rich going to find another weak link that is still hiding somewhere?
Another question is, why wouldn't Marantz avoid the use of OPAs in the HDAM modules of the 8801, or at least use higher quality ones? Even if it was just a cost/profit issues, they would have to be convinced that Audiophiles (the obvious targeted market at the time) wouldn't hear the lesser performance of those low cost OPAs. If that is true, then Marantz must have upgraded the HDAM in the 8802 purely for marketing reasons, and that would be still be consistent with what Mr. Belanger had said when he defended the use of the OP amps.
Reality though, now that we all know 8802 has better spec components in the preamp section, most of us will in fact begin to "hear" improved sound. Professional reviewers have already done the part.

Regardless, I do think the HDAM and other upgrades Marantz has implemented in the 8802 is a very welcome news, especially if I were in the market for a new prepro. The point I am trying to made is that there are important underlying messages in all these. What you don't know won't hurt you, is one.