Monitor speakers that disappear:best image/staging

Have you considered that speakers have different radiation patterns and how they perform can be affected by both set up and toe in. Some want to be heard well off axis (pointed straight ahead) and some work best toed in?

When I encounter those speaker types you see as problematic I assume, first anyway, that it is a toe in issue and will experiment with the degree of toe in up to the axis crossing in front of the listening position. Placement wise I consider how they perform near boundries or distant from boundaries. I also consider listening position distance from the speakers. It all makes a difference in how well your speakers disappear.

Toe in can also change the (negative?) effect of sidewall reflections experienced in small rooms when the speakers are placed too close to the side wall.

FWIW, when dealing with reasonable good high end speakers, monitors or full range, I think set up is a huge issue and most can sound pretty good.

If you haven't already done so I think I would devote more time to set up than to finding new speakers IF imaging is really the problem you are trying to solve. And BYTW, balanced hearing accuity is not set in stone, i.e. constant and balanced ears.

Frankly there are a lot of full range and monitors that do the disappearing trick very well, but the real issue with them is about tonal balance and room synergy. Hard to make recommendation of these in a vaucmm (no info regarding sonic preferences, room dimensions, and set up limitation s if any.

FWIW.

I thought monitors were well known for their uncanny ability to easily
disappear , image very well , and throw a large soundstage when properly
set up. This has beene experience owning monitors. I have also read tons
of reviews of monitors where the reviewers are always mentioning their
ability to disappear, image, and through a wide soundstage, with great
center imaging.
I didn't think you had to spend big dollars on expensive monitors to achieve
the solid image and sound stage, but rather most monitors could perform
this with proper set up and room treatments if necessary.

What Todd said. If you place monitors on rigid, non-resonant stands, properly placed, you almost always get killer imaging, particularly when the front baffle is small and sculpted to minimize reflections off the baffle and edges. On a budget the PSB Image B5 and B6 will give you a lot of what you're looking for.

You can also enhance imaging by integrating a subwoofer (or two) into the rig. There's something about adding the foundation that makes everything else pop out more.

Generally speaking, the ones with the least front baffle area and with some sculpting to avoid refraction distortion. Monitors are usually 2-way speakers, simplifying the crossover scheme and providing some advantage in maintaining phase coherence, which is another element of throwing a good soundstage with good imaging.

At a higher price, but not insane money, the monitor I really like is the B&W PM1. I heard a pair in a demo with B&W's PV1D sub. The overall effect was engrossing in every way--timbral accuracy, pinpoint imaging, dynamics, pace, etc. I had just previously heard the Wilson Alexandria XLF's, and this PM1/PV1D combo communicated a great deal of the same musical truth, albeit on a smaller scale. Matched to the right room size, though, the PM1/PV1D doesn't sound small at all.

Definitely check out the Shelby+Kroll Nano monitors. No matter where you sit they sound great and the soundstage never collapses. I'm starting to sound like a broken record but more people need to hear these speakers