plugging in a pair of 803's in a unconditioned room with medium level electronics is not a fair comparison with your system.
Stan,
I understand what you're saying, but I don't completely agree and I'll try to explain why.
Firstly (and perhaps unfairly) you've made me think back (and hard !) - I should have mentioned that my system changed from the DM604S3's & a Denon 3802 Receiver to the N803's, and then some of the TAG McLaren kit, which has been subsequently added to over the years. And it has been a real evolution, so I've been able to compare components over a reasonable period of time.
By the way, the TAG DVD player never ever cost that much - even when it first came out - but it's still a "fair call" as it wasn't cheap ! No idea where the reviewer got his price from....
Also, I demo'd the change in speakers at my dealer as well which is when / where I decided to go for the significant upgrade - and they also operate a reasonable trade-in programme which encouraged me just a little....
In short, with the experiences I've had I think I'm able to say that, with medium-level electronics, the difference in speakers that the OP's alluding to will be very very audibly significant indeed - but let's wait & see if that's also his conclusion after his audition ! But again, remember that this is my opinion which anyone can take or leave....
Also, to set the scene a little, my room isn't very big & I've only treated the first reflections. This is because my room's very "busy" so there's not really any space for more absorbers, but also because my TAG processor has room-correction - one of the reasons I almost bankrupted myself (again !) to buy it.
Finally, over the last 2 weeks I've had to lose room-correction & a "link in the chain" as my TAG processor went "pop" and my dealer has loaned me a Rotel RSP-1570 while the TAG's being repaired.
Thus, no speaker change for me, but a hardware change. The sources have of course all stayed the same, and the power amplification too, but the "hub" is different - and there is a change in the sound to my ears (compared to my TAG with the correction switched off). Now, I can't tell you how much (to my perception) the sound quality has degraded : 5% ? 20% or 50% ? I don't know - because is "quality" really measurable ? However, it has changed - perceptibly, but only a little.
And of course we're talking about 802D's, which are again a step above the N803's.
Now, before people shout "expensive kit & only a little change = proven madness !?" then I accept and actually only expected a small change with the Rotel anyway, because you can demonstrate & measure that in any system the speakers have the most influence on sound - which is obviously connected to the room's acoustic behaviour, with the sources coming next & the amplification hopefully coming last. Don't even get me started on cables !
I say amplification last because an amplifier shouldn't have any "sound" at all - that's colouration - and in my book (again, only personally) that's totally wrong. To clarify with a common example, some people like Sonus Faber speakers & McIntosh amps because they sound "smoother / warmer". Well, that's because of their design - and it's deliberate - but the facts are that they're designed to change the signal that they're fed & output something else.
My goal is to hear what's on the disk or whatever source / software I'm feeding my kit from - I want total transparency - that's my aim - and that's why I've gone for B&W speakers + TAG McLaren electronics. If something sounds awful on my system, I want to know about it !
So, like I say, let's wait & see what the OP thinks - after all, at the end of the day, it's all about personal enjoyment and everyone's different - but as a logical / rational / skeptical person (yes, I'm an Engineer !), I try to be as objective & unbiased as possible - and of course I try to be helpful too !