Floor-Standards to Monitors?

Monitor Audio are superb. 

Too many variables to make a blanket statement here as @audiokinesis mentioned in his last paragraph, but I’ve also thought about this quite a bit myself and have a couple thoughts.  But to answer a couple of your questions, when audiophiles are frequently spending $30k+ for speakers, spending more than $5k+ on very good monitors seems very reasonable to me.  And no, I don't think DSP/room correction, although quite awesome when used properly, can make up for all the advantages larger floorstanders can provide...

First, if you’re talking about large, multi-driver speakers or line array speakers IME there is a soundstage size/scale, coherence, dynamics, and perceived effortlessness thing going on that I just don’t see a monitor and subs being able to match. Period. Size and physics still matter.

Short of that size/scale, etc. thing though, and more focusing on more reasonably-sized 3-way floorstanders, I think the lines get much blurrier.  And this is where all the variables really make the ultimate answer very situation and brand specific. I’ll use one specific case I’ve been considering that I think brings some of these things to light. One of my potential end-game speakers are Joseph Audio Pearls, but they’re currently way out of my budget and may remain so. So I’ve thought about pairing Pulsars with a couple very good value priced subs from the likes of SVS, Rhythmic, Hsu, etc. or a swarm-type setup to create a "Mini Pearl," which would cost around $20k less than new Pearls. (I use Pulsars not only for personal taste but also because they can reach down fairly low on their own, which I think is important in trying to achieve similar seamlessness and dynamics to full or near full-range floorstanders -- not sure smaller monitors that don’t go much below 80Hz could pull this off). Now, although the Pulsar very much shares the JA house sound (and tweeters) with the Pearls, the Pearls have a more substantial and dedicated midrange driver that I think will give it an advantage over the Pulsars with subs (PWS) in dynamics and coherence (among other things) that I can’t overcome. But, on the flip side, I’d expect the PWS to reach significantly lower and cleaner in the bass range -- very possibly better coupling with my room and assuming I’m using good DSP integration technology -- that could bring significant advantages in that area (let’s leave the amp not having to work as hard thing out for purposes of focusing on speakers here, but we all know that’s a big potential factor here as well). Now, even if I can’t match everything the Pearls do with the PWS setup, I’d bet I’m getting pretty darn close with an extra $20,000(!!!) in my pocket, thankyouverymuch. Let me repeat that number -- TWENTY THOUSAND DOLLARS. Just think of what else you could do with that much disposable income. The Pearls would have to conjure up quite a bit of synergistic magic to fill that big of a monetary hole.

But there’s another option. What if I ponied up for the Perspective floorstanders and paired THEM with subs? Now I’ve got two (or, maybe more technically accurate, one and one half) of the Pulsar’s midwoofs working to replicate the larger midrange driver of the Pearl, and I can cross the subs over even lower since the Perspectives produce more and lower useable bass than their monitor siblings. I’d think I’ve now closed a good bit of the dynamics and coherence gap that existed in the above PWS configuration, thereby coming even closer to the Pearl’s level of performance. But, as per the OP’s wish list, I’ve still got small floorstanders that are very easy to move around, and I’ve also still got about an extra $10k in my pocket!!!

All that said, if I had the scratch for the Pearls would I choose either of these options instead? Nope. But to be honest I’m an idiot, and I don’t plan on moving my speakers around at all and can still add a couple good subs and create my own "Super Pearls." As Sam Tellig used to say, "I laugh my evil laugh." It never ends, right???

Anyway, I used this specific example not to be self serving but because I think the same variables here can be applied across several brands, and it surfaces a lot of the basic issues on which I think the OP was looking for thoughts/feedback. Peace out.

Much happier with my monitors and two subs but, in fairness, the monitors have two 9-inch woofers in each sealed box and go very loud wIthout compression, the sealed-box (acoustic suspension) bass is excellent down to 40hz

I too am getting older and wanted to be able to move speakers around (constantly) by myself. Had Merlin floorstanders for 15 years then switched to monitors and found I preferred them. I have a small dedicated listening room 11x18 and listen to acoustic music (classical and jazz) at low to medium volume. I ended up with 2 entirely different sets of monitors, Harbeth 30.1 and Revel M126be. When I get tired of detail, I switch to the Harbeths and then when I crave detail, back to the Revels. I love both but they are night and day different. Note that if you didn’t like the Personas, you might not like the M126be’s. For my taste, I thought the Persona B was one of the best but ended up with the M126be’s instead.

I’ve heard a lot of live music and the 30.1s sound like live music. The Revels have more WOW factor and are surreal. I use two small subs, REL T/zeros, rolled off at 40hz with one sub at 0 phase and the other at 180 so they don’t fight each other. Subs are at very low volume. I don’t like a lot of bass but find that the two small subs in stereo at low volume settings add just a touch of fullness.