B&W 804's Vs. Vienna Acoustic Beethoven

You're correct on both accounts: the N804 has a very lean (im)balance...B&W's attempt to make a small-scale 803N to satify the US distributo's request for a lower price-point item is quite a failure! As well, ALL Nautilus require a rather distant listening position in order for the drivers to cohere properly. The 803N requires about 12' before it snaps into focus. I doubt that the 804N EVER does! Ha!
In contrast I've only listened to the Beethovens briefly, but was much more positively impressed with them than the 804. If you listen in the nearfield you have other choices; if in the farfield, I'd get used 803N instead of the 804N new...but only if your sidewalls are damped enough
to tame that splashy tweeter, too! In other words, the 803N requires a LARGE room. Just my limited opinion...good luck!

Right on Subaruguru. B&W is garbage. The fact that they are among the top five largest speaker mfg'r in the world shows how effectively they have brainwashed people all over the world. They are the Bose of high-end. The entire Nautilus line is a failure.
Scott, may want to consider upgrading the Denon along with the speakers.

I've sold both lines, and I don't think the 804's sound very good overal! I like em quite well actually, especailly bi-amped. I wouldn't necessarily rate the Bethoven's any higher overll either. But then I'm not a big Vienna Fan. Personal taste will win out there.
Also, consider that set up, room acoustics, proper associated equipment, etc, all will determin what you heared from those AUDITIONS you had! It's too hard to tell in DIFFERENT ENVIRONMENTS, in different situations...just not a fair comparison.
I have however had very good experiences with the B&W 804's in the right system/room. They do a lot right for the money..and I wouldn't call em GARBAGE!..as one personal called em. While I have come across higher end speakers than the B&W's for sure, they certainly aren't slouches or junk. Infact they make fine speakers at all price points, including the N800 series.
Yes, be sure, the DENON receiver(like all receivers) will be a weak link in your system. With this level of speaker, you should be considering saving for SEPARATES..IT'S JUST NO CONTEST HERE! However, depending on your budget, the speakers are the most important part of the gear-chain.
Keep in mind, if you're looking for DUAL PURPOSE higher end speaker, that the room and set up will have a lot to do with what's going to work well and what's not!!! If you have low ceilings, and/or sit back further from your speakers in proportion to WALL PROXIMITIES TO THE SPEAKERS, a standard traditional MUSIC SPEAKER (like the Bethovens or B&W's) aren't going to work so well ideally!..especially for HT! The sound will be more colored, the immage more BLURED, the dynamics and focus of the sound will be SOFTER and more DIFFUSE sounding! Unless you have MAJOR ACOUSTIC TREATMENTS in your room in this situation, or you sit CLOSE to your speakers in a smaller room environment/set up, you should STRONGLY consider a more HT friendly, and even dedicated cinema speakers!
There's a reason ALL THE HT MAG reviewers and STEREOPHILE writers and such use DEDICATED HT SPEAKERS for their HT systems!..they work better! And there's some very very musical and MUSIC FRIENDLY HT types of speakers out there, or speakers that do HT BETTER at least. If you notice the vast majority of these guy's use either DIAPPOLITO, HORN LOADED HIGH END SPEAKERS, THX DIAPPOLITO monitors, or other more CONTROLLED FOCUSED SPECIALIZED speakers for their HT's.
There are quite a few hi-end, more refined speakers that won't cut you short of what a good DD/DTS movie soundtrack has to offer, and will sound superb on music as well! If you look closely at all the reivews for equipment in some of these magazines, such as HT mag, Stereophile Guide to HT, etc, you'll notice what speakers and gear these guy's have in their REFERNCE SYSTEMS personally!!! Trust me, they know what works well, because they've heard most everything, for every purpose!!!!
Personally, a lot of what I would recommend for your application, would largely depend on what your room set up looks like! This will have a lot to do with what you can and can't do to be the most effective with your speaker chioces.
Good luck