New Speaker advice

Goodonya for taking the time to go out and seriously listen and, most importantly, having the guts to trust your own ears! Unfortunately I can’t help with the speakers, but I would very highly suggest you consider inserting a good stereo preamp into your system at some point instead of using the preamp section of the Denon AVR — your nice amp will thank and greatly reward you for it. Trust me, the Denon’s pre section is a huge bottleneck to getting much better sound out of your system as a preamp is an absolutely critical component. Just my $0.02 FWIW, and best of luck with the speakers.

Denon AVR line has a 'pure direct' mode where it supposedly shuts off the internal amps completely and sends a 'pure' signal from amps to speakers...so that's what I use in 2 channel listening...but I am suspicious of it still bottlenecking as you describe

Yeah, you’re very right to be suspicious.  The problem is the sensitive and relatively low-level line signal is still going through the cheap preamp electronics of the AVR, which is the heart of the problem.  Think about how much you paid for the Denon — how much do you think they spent on the stereo preamp section in it?  AVRs are designed to hit very aggressive price points in an uber-competitive market, and the first thing to get sacrificed is parts quality (think critical/expensive parts like power supply, capacitors, etc.) and is why they’re so compromised from the get go. Do not minimize the importance of the preamp, and at the very least I’d encourage you to try a good stereo pre in your system just to hear for yourself what you may be missing.  Lots of places offer trial periods these days, or you could buy something used at a nice discount and that minimizes your risk if it doesn’t work out.  Sorry to be so wordy, but this is really important so thought it was worth going into a little more detail. 

but in my system, they sound quite veiled and choked...which is a criticism those speakers have earned over the years...but yes, maybe I should try preamp upgrade first! 

Completely agree on your impressions of the 3As, at least the older versions — haven’t heard the newer ones but Vandy speakers have definitely upped the treble detail with their newer models.  I heard the 3As many years ago (so maybe same version you have) with some good Quicksilver electronics and with my reference recordings, which I’d heard on many, many systems in addition to my own (and several that cost well north of $100k), and the 3A’s top end sounded rolled off and dull/lacking energy or life — kinda like someone threw a thin cloth over the tweeter if that makes sense.

If I were you I’d upgrade the speakers first because the 3As may not have enough upper-octave detail to completely reveal a preamp’s capabilities or character in that area whereas the speakers you’re looking at now will likely very clearly expose differences and which pre is right for you.  Plus, those are the speakers you’ll ultimately be using with the preamp so it’ll be very good to know there’s synergy between them that works for your system and tastes.  I think you’re totally on the right track here and that your system is about to take a monstrous step forward and that all your effort is going to be hugely rewarded.  Keep us posted if you could. 

I agree with everyone that using the Denon is spoiling the experience, but adding a preamp with HT bypass is the wrong approach in that you will be powering your two channel with the Denon power amp.

@tony1954 Yeah that’d be a total mismatch, but if you look at his equipment list in the original post he’s using a solid Audio Research D300 amp for the front L/R so he’s ok there. 

I always recommend focusing on the weakest link in the audio chain. Your Vandersteen’s are definitely not your weakest link.

@nordicnorm Although I agree with your basic strategy I have to disagree in this specific situation.  While the older 3As are certainly well-regarded classic speakers and for good reason, their characteristic rolled-off treble is clearly not to the OP’s liking and won’t be fixed by adding a new preamp.  Plus, that lack of treble detail will be a disadvantage when evaluating stereo preamps as they will mask important information precisely in the area where the OP has issues.  He’s clearly gonna upgrade the speakers, which is why, although not optimal, I suggested upgrading speakers first in his system as it is and then use them to choose the preamp that synergizes best with both the new speakers and his specific tastes.  Could be wrong, but that’s definitely the way I’d approach it in this specific situation. 

As you’re in the Philly area I highly recommend, if you haven’t already, going to David Lewis Audio and listen to some Joseph Audio and ProAc speakers.  They both have excellent detail but don’t throw it at you and present it in a very natural way, and they both disappear and throw off incredible 3D imaging and soundstage — especially the Joseph Audio speakers.  You may well find yourself mesmerized by both.

As for integrating preamps without a HT bypass it’s doable and very easy.  I won’t go into details here but it’s not a big deal to make it work.