Hope this helps, we have a customer with the Montis, sold years ago the JM Labs, and have heard the Magico S1 at numerous shows.
The concept of adding a sub to a mini monitor doesn't work that well in real life, the sub never sounds completely blended, and the monitors will sound bigger, but will still sound smaller than a true full range speaker.
The Magico S1 are good but do not have the same sense of richness in the midrange as the JM Labs. The S1 tweeter is good but believe it or not the Diamond coating on the Magico actually over damps the Beryilium tweeter leading to slightly recessed upper treble.
The new A3 may be the better, it is a true three way and it is half the price of the S1, only time will tell once they are released in February.
If you want a spooky transparent sound, a huge sound stage and a very tight deep bass, look at the new Paradigm Persona 3F or the larger 5F.
The Personas have the speed of the electrostatic speakers with a more holographic sound stage, they are very revealing.
The Personas use the most advanced drivers on the market today with a pure Beryilium tweeter and midrange, coupled with some magical technology called a phase aligned lens which shapes the waveform to eliminate out of phase info, the result huge focused soundstage.
The Paradigms are a tour de force design from Paradigm.
The Montis are great all around speakers, the biggest issue with them is a slightly recessed upper treble and they are not super dynamic, they are also diapole which means they will bounce equal energy off the back wall, therefore the image will be big but diffuse.
You need to go listen as carefully as you can to all of these speakers, they are all excellent.
If you are in our neck of the woods you should give the Personas a listen they are pretty fantastic.
Dave and Troy
Audio Doctor NJ