smaller speakers for critical listening?

This is a great question.  I personally prefer monitors to floor standing speakers.  I owned Infinity Kappa 8.1s for many years and was quite satisfied and then I got married.  Not surprisingly my (now ex) wife was not a huge fan of 4' high, 15" wide speakers.  One of the few things my ex-wife and new wife have in common is their animosity toward large speakers.  

I started hunting for new speakers and listened to probably 30 different products and ended up with stand mounts/book shelf speakers as they created a lot of flexibility in terms of placement.  But couldn't get over the fact that the sound was a little thin in my room which was 13 x 20 and I was sitting 15' from the speakers.  I got a better/different amp and it helped.  Then in a larger room, 15' x 30' with vaulted ceiling those same speakers just sounded tiny.  

For a long time I would make the argument that stand-mounts are better because the optimal placement for mid and treble reproduction is often different than for bass.  And this is true but at a root level, some stand mount speakers sound small and can't overwhelm the size of the room you find them in.  

Not all small speakers sound small.  I talked to Andrew Quint who writes for TAS.  He reviewed speakers under $20K from AXPONA and said the thing he was really focused was the juxtaposition of little speakers delivering big sounds or big speakers delivering little sounds.  

It is possible to get close to a full range experience in terms of soundstage, especially with a properly integrated subwoofer but it does require care in selecting the right speaker.  I am 100% certain it can be had in the price range you have outlined. 

The real questions become, what do you want in terms of sound profile?  If you are replacing maggies, ribbons or AMTs will offer interesting options if that is the sound profile you like. 

What is the challenge you are facing in terms of placement?  Is it distance from the wall?  Width?  Both?   Many stand-mounts need room from the back wall due to porting and even if they are front ported doesn't mean near wall placement works.  Distance from the back wall absolutely impacts how the soundstage comes together.  Also, are you open to adding a subwoofer?  

Other things I am not seeing.  What amplification are you using?  That will very much impact the sound and what speakers you can drive.  Will that change with with a new speaker selection if need be?  

There are a million brands and the key is getting one that will deliver the sound you want in the space you have.  The best way to evaluate that is in home.  I can think of a variety of products that make sense in terms of sound but need to understand other variables before a wise recommendation can be made.  

At a root level...the answer to profs question of "can you be truly happy in the long run with a small speaker" the answer is it depends on who you are.

I am now at 8 years with small speakers and likely will not go back to floor standers any time soon if ever. I have had Sunfire HRS SATs, B&W M-1s, Revel Performa3 M105s, Raidho X-1s, my own Verdant Audio Nightshade & Blackthorns, Scansonic MB-1Bs and I am probably going to get a pair of Audiovector R1s here soon. I am all in for stand-mount speakers but that is my preference. Without a subwoofer, the image is decidedly smaller. With a subwoofer...it is close assuming the right speaker. That is the key. (And this is not just because I only produce stand-mounts.  I have begun working on floor standers).

How do you find a speaker that has the right tone that you react to in the right way? When you say critical listening, are you looking for refinement and accuracy vs. listening experience and musicality? I had a blogger over to listen to a few speakers and at one point, he commented on the two speakers we were focused on and said "this is definitely the better speaker but that one is just more fun."  There is an element of refinement and excellence but also musicality and enjoyment.  

The only way to do that is listen. Schedule appointments. Use the same tracks and take copious notes while you are listening. Focus on a narrowed list of both types of speakers. If a speaker fails vs your test, don’t waste your time. I have a series of six tracks that I go through that if a speaker didn’t check the box I was looking for on any one of them, I would just move on.

Finally, on the note of small speakers sounding big. This is extreme, but read the review in the Absolute Sound of the Raidho TD 1.2s. They are $23K list price speakers but the reviewer ran an experiment where they brought three people in to listen to them blindfolded and asked them what they were listening too. Two of the three thought they were listening to electrostats or planars (admittedly not full range). That immersive sound experience can be achieved at prices below $23K but that to me is what we are all trying to achieve when producing small speakers that deliver big and immersive sounds.

If and when you are ready to demo, you ought to check out Audiovector R1, Raidho X-1, Monitor Audio Platinum 100s, Magico A1, and I would encourage you to stop by and listen to my (verdant audio) Blackthorn & Nightshades for small speakers that sound big. Verdant obviously only if you make it to the NYC Area.

For small floor standers, the Audiovector R3 (read Andrew Quints review in TAS), Scansonic MB5 B (Raidho floorstanders are very pricey),Verity Finns, Vandersteen, Spendor D7.2 and 9.2, Magico A3 and for a speaker that is large for a stand mount but not really and floorstander, the Harbeth 40.2 are all very much worth your time to listen too I think.

There are countless others as illustrated by this another threads. These are just ones that I have heard and know sound excellent and I think will age well and limit the yearning for...more.