Speakers costing range of 2500-3500 per pair

Nope. You need to dump the Denon. The Focal and Sierra are designed to handle major amplification. The Denon does not have the power reserve necessary to bring the Focal and Sierra to their best performance level. Dealers are like politicians, they'll tell you exactly what you want to hear. Rule of thumb matching an amplifier to a speaker for maximum performance. Under powering a speaker at high volume levels will heat up your drivers and cause damage. When a company list specs such as amp recommendation as " 100 to 300 watts " , always go for the max. To determine the correct amount of power, call the speaker company and talk to their tech designers, and ask them what is the maximum continuous power their woofer magnets can handle and divide by two. If you are told 500 watts, then 250 watts is what you need. The Parasound A21 amp would be an excellent choice at 250 watts per side and you could pick one up used, as an example. You always want your drivers current volume at least 50% at all times to keep your drivers and crossover components cool for the very best performance. I would go for the Sierra's, much cheaper since their factory direct and you would save about $700, sell the Denon and if your on a tight budget, pick up a used Class D integrated from Wyred 4 Sound, to provide the power you need.
Go to the Ascend Acoustics website and read the review by Enjoy the Music of the Sierra Towers. Review is outstanding.

                 www.ascendacoustics.com

@audiozen

Nothing against Ascend speakers. I haven’t heard them but from everything I’ve read, I have no doubt that they’re at least competitive with others mentioned here. Owners seem to love them. Do you own a pair? As far as materials are concerned, I wasn’t referring to tensile strength, I was referring to resonance characteristics, where MDF has the advantage over many materials. Besides, compression strength is the more important factor, which is why Magico and others use carbon fiber cabinets, not bamboo and aramid.
Best regards.

helomech..I was referring to organic materials only. Not synthetic like carbon fiber which is made up of polyacrylonitrile and rayon. Very bad material for the environment. Cannot be recycled and it winds up in land fills. China is currently developing an alternative, bamboo carbon fiber, which I'm not sure how green it will be. I heard that Donald Trump is having a pair of Magico M3's dipped in gold to put in his bathroom at the White House.

audiozen has a beef with Vandersteen and it shows in your posts.  That alone makes anyone question what you say.  You have the general idea about pricing down, but not in all cases.  That's a fact. You speak in absolute terms and fail to realize that many dealers carry equipment that is much better in sound and quality than direct sell.  Not in all cases and that's why I own a bit of each in my own system.  I just want what sounds best for me like most folks seem to want.  

You can speak in absolutes all you want about cabinet materials or expensive drivers and crossovers used, but that means nothing if not implemented correctly.  Maybe the Accent guy does that, but they still won't be the right speaker for everyone.  I love Vandersteen's and Tidal and a few others right now, but that doesn't mean that everyone will or should.  This is why there are a ton of makers out there.  

If a direct buy company doesn't offer at least a 30 day 100% money back guarantee, then I personally won't purchase from them unless they bring the product to the house (yes, I'm lucky since some folks are close to CT).  Maybe that speaker company does that.  If so, good on them.

As for Vandersteen using ghost writers, I highly doubt it.  As for his temper, who knows how you were with him.  It takes two to communicate.  I know a few folks who have had negative conversations with some of the biggest gentlemen in the industry.  It's ironic as I've overheard Richard speaking with an engineer about design concepts etc...  He may not be an engineer on paper, but he surly seemed to know what he was talking about.  Not all engineers have a degree or need one.  They can be self taught too.  

I personally don't care too much about all of that as I'm more into the music and great sound.  You can get that from a variety of components and matching as you pointed out in your Denon response, is THE key thing.  No need to purchase anything if you aren't going to match it with the correct devices.  Thats' at all price points I personally believe. 

I'm not going to disparage anyone or any product in this thread as I don't have a beef, like you admitted to with anyone.  The OP needs to get out and audition as many products as they can in order to figure out what they really want.  When folks actually get to stores and listen for a bit and not let the dealer or the manufacture talk them into something, they will find out they really do like one thing over another.  So often folks don't think amps or pre amps etc, really make a big difference until the sit down and listen to a few of them adn notice that they may not want what they came in look for.  I had that happen wiht me when I thought I wanted Vandy 2 back in the late 90s and walked out with a pair of floor standing ProAc's instead.  

Clock forward to about 4 years ago and I went into the closest ProAc dealer as Richard G (former distributor) sent me to Audio Connection.  I wanted  to purchase a new pair of the newer D series monitors and I walked out with a pair of Vandersteen Treo's.  The owner forced me to listen to all the speakers in my price range, because we all hear differently.  

OP, forget all of us and go listen.lol