Scale and dynamic impact. I have been discussing the importance of the sense of scale (as in large scale) as a parameter of performance for some time now. It is not typically discussed, only terms such as "large soundstage, etc. Not the same, as any one who did comparisons as you have can tell.
No, smallish speakers with subs do not come close to the big guns. Consider that the crossovers, drivers, configuration, elevation, etc. is all different - all of these fundamentally superior in a more dominant speaker (for illustrative purposes, we would be supposing models from the same manufacturer, but in general still holds true). I have used several sub/monitor systems to assess that very thing, and I have turned away from every one of them back to larger floor standing speakers because the sub-monitor can't get it done the same way. Unless the driver configuration, crossover, height, etc. are identical, you're losing by going with sub/monitor. Those are just the hard facts, not a judgment of one's choice.
In fact, in my experience the sense of scale can trump even the genre of speakers! I would rather listen to a fine speaker of a different genre than my ideal, than to suffer the shortcomings of a smallish speaker of a more preferred genre. Then again, I have grown to appreciate the idiosyncrasies of many genres of speakers. I have worked with large OB, Panel, Hybrid dynamic, array, etc. speakers and they all carry a grandeur that simply cannot be replicated in smaller speakers. For good reason companies build monstrous sized transducers! :)
I am working on a big floor standing speaker review currently, and the experience is fundamentally different than a speaker of smallish stature. FAR more opportunities to impress with a big speaker.
