I agree pretty much with Robbo and Stephen - and MP is just doing his usual s**t-stirring. BTW thanks for the compliment Robbo - and I can assure you that its now a lot more lively, open, dynamic, detailed and smooth

than when you last heard it (but maybe a bit bass-light for you).
The first high-end system I heard (Metronome CDP, Lamm pre and monos, WB speakers) was seriously underwhelming - I really couldn't see what the fuss was about - no scale and dynamics (10W SET valves), but the real surprise was that it was detailed
without being clear

! I also wasn't too impressed with JJ's megabuck system. Yes it was beautifully clear - but to my ears the top end had a really thin a wispy quality - so you got a beautifully accurate presentation of the fact that you were listening to speakers. (Chris' comment is also interesting, as - despite a predisposition to do so - I've still to hear a ribbon tweeter speaker I like).
At the kind of levels many of us are here, I think the limiting factor becomes dominantly one step along the food chain from the source, i.e. the
mastering. CDs (or LPs) are mastered to sound good on some particular piece of kit - usually something much less revealing than what we are talking about. As such it will have certain features overemphasised to cut through the target system weaknesses. When put through higher level kit those emphases will come out and hit you - making the music sound artificial. Note that this is not bad mastering - just targeting for a different audience - and due to the number of Walkmans, midi and in-car CD systems would most likely affect CD more than LP.
It also probably affects classical less than more popular music (apart from anything its dynamic range makes it quite difficult to listen to in the car), which is why we may go for more hi-fi type systems. And as Robbo has said, the tonal balance and fine detail is far more important to most of us than is the ultimate in leading edge or pace - but it you can get both then so much the better.
I've not got any CDs from audiophile labels such as Reference Recordings (they tend not to capture the great performances), although there is an RR version of my favourite Bruckner 4 (Wand/BPO live), it would be interesting to hear that through a top-notch system.
(It would also be interesting to hear the views of Skalamboukas or some of his members on this subject)