Vandersteen 2/3 vs. 3A MM de Capo vs. GMA Europa

I would like to upgrade my modest system:

Squeezebox (stock) playing FLAC files
Rogue Audio 66 Magnum
Threshold S/200
Onix Reference 1 monitors
ACI Force XL subwoofer

I have a large room, about 14' x 28' (somewhat irregular shape) that is open to another room and a corridor.

I think that speakers would be the best upgrade at this time and the three I have mentioned in the title are high on my list (I haven't heard any of them so it is based on what I read here). I’m interested in other suggestions. The budget is $1500- $2000 used, depending on whether I need to keep the subwoofer.

I often listen to music many hours a day so non fatiguing sound is important. Also I don't always listen from the sweet spot and I would like speakers that sound as good as possible throughout the room. I often listen at night at lower volume. I listen to all kinds of music; almost everything except orchestral and hip-hop/rap .

I’m new to this hobby and I’m not sure I know exactly how to describe what I’m looking for. I want a more room filling sound and for the speakers to disappear (that is sometimes a shortcoming of my current system). I like details and good imaging.

I should mention that one of the reasons I’m considering 3A MM de Capo is because I might want to try a tube amp in the future so higher sensitivity speakers would be useful.

Am I on the right path thinking about the speakers or should I consider changing the electronics? I would appreciate any specific suggestions but also general advice how I should go about the upgrade.

Look at Devore Fidelity Gibbon 8's and enjoy.
The Vandersteen 3A sigs will make most sense and fill that room best.
The Vandersteens offer lofty drivers are full range phase and time correct from a great company that answers the phone real time.
Would my Threshold (it is 100W/ch) be enough to drive the 3A sigs? Is the room too big for 2ce Sig? I read they are easier to drive.
he vandys(2 or 3) are the 'fullrange' alternative here, and probably the most for the money. You would have to move up the 3A or Green Mountain line (next model up) to get a comparable 'choice'.
The basic character of the Vandy 2 is very different from the deCapo (I don't know the GMA). Both speakers do feature a relatively "polite" high end so your concern re: long hour/fatigue shouldn't be an issue with either choice. But, the Vandy's have both much more bass extention and more overall energy below the mid-range which shifts the octave to octave balance toward a warmer character while the deCapo feels more analytical (if you're not a fan of this tonal character) or tansparent and detailed (if you are). Choosing between the 2 is really a matter of personal taste, but I suspect that almost everyone who auditions these speakers will have an easy choice:

Personal priorities will take you one way or the other, but you probably won't have a hard time deciding.

One other note: If you keep your sub, you may be able to "dial away" some of the difference. I'd personally suggest that you consider budgeting $500 to $600 for a Velodyne SMS-1 sub controller if you decide to keep your sub and add the deCapos. It's a great product that includes a flexible active low pass, a more basic high pass, room analysis and PEq. The SMS allows seamless integration of your sub and mains and also allows you to eq for smooth response in the deep bass.