Warmest sounding Green Mountain speaker?

Personally I think the GMA speakers work well with all types of music. But that transient speed is what makes them shine with acoustic music like bluegrass.

Shakey

I havent heard the bigger GMAs but the bookshelf models I have heard are clearly flawed in the bass region IMO. The mid-upper bass which gives an acoustic instruments its woodiness character and to some extent the body was lacking seriously IMO.

Agree. The lack in the mid upper bass is due to the tiny cabinet volume of the bookshelf models. Anybody know how many litres Rio uses?

Apart from that, the driver they use is an aurasound woofer. For the price of Rio, you would expect accuton or scanspeak revelator etc.
Not a $20 woofer!

I've had the Green Mountain Audio Callistos in my system for the past ten years and have not had the desire to upgrade speakers since that time.  Before that time I was always looking to upgrade my speakers.  If I ever do upgrade it will be to another newer Green Mountain Audio speaker.  I've listened to four of their models and they all have a very similar sound signature from the upper bass on upward.  Most of the models use different drivers but I believe the sound is so similar due to the unique first order crossover and dead quiet cabinet construction.
The speakers are very efficient, easy to drive and play very loudly.  Transparency, soundstaging (especially depth), microdynamics, inner detail, and reproduction of the human voice are extremely well done and I really haven't heard better in those areas from most other speakers I've listened to. Six moons gave these speakers a phenomenal review ten years ago.  I've had several members over my house from an audio club I belong to and all agree they are first rate speakers and cannot believe such sound quality coming from relatively small monitors.
I do agree that the monitors do not have a lot of deep bass however the bass is very tight and controlled.  I'm using a Rel Storm III sub which integrates seamlessly with the Callistos.  I'm using a hybrid integrated amplifier so I agree having some tubes in the playback chain is worthwhile.  I have not compared them to the Vandersteens.
Just my opinion.

Apart from that, the driver they use is an aurasound woofer. For the price of Rio, you would expect accuton or scanspeak revelator etc.
Not a $20 woofer!

kenjit, it's not about how much a woofer costs w.r.t. the total cost of the speaker that dictates whether or not it gets used. It's the specs & the freq response that it far more important as that tells the speaker designer how it will integrate with the tweeter & midrange. So, if a $20 woofer has the correct attributes over a $200 Accuton woofer, then, the $20 woofer will be used. I'm sure that Accuton builds good woofers but for this particular Green Mtn Audio speaker the Aurasound woofer was a better fit. I know that Roy is always looking for the best drivers & I understand that the choices are limited to independent OEMs. So, that also puts a big constraint (unless the OEM wants to order a very large batch of Accuton drivers as a minimum order from the manuf which many small OEMs cannot afford).  
I've heard a few Accuton-based speakers incl a stand-mounted Tidal - I cannot say that i was impressed with the sound. The Green Mtn Audio speakers sounded way better to me. 

There is no minimum order for most drivers including scanspeak. you could buy one single accuton driver if you wanted to.

It’s a question of getting your moneys worth. If the parts used in the Rio/chromatose only cost say $100 yet it is sold for nearly $4000 the price you pay is going towards the rent for the factory and profit. Your hard earned money isnt going into the product you are spending it on.

Now the basic Rio model costs $2800 but they are charging you $1000 bucks more for their magic wire and burn in process. Audiophiles need to be educated so that they dont fall for this nonsense. Ask for proof that any of this makes a difference.

For $4000 you could buy a whole hifi, or a pair of devaliet phantom etc.
There are many more companies now producing products using more technology for less money. If you pay $4000 and all you get is a $20 woofer a few crossover parts, and a marble cabinet, it doesnt seem to me like good value. But then again, you could also buy $4000 interconnects so its up to you whether you want to spend your money wisely or stupidly.

As I said before, if you want to feel how much distortion is going into the Rio tweeter, just put your hand on the tweeter while the music is playing and feel the vibrations. Tweeter are not designed to play such low frequencies. The seas tweeter they use rolls off at 1khz. So you should only be using it down to about 1500 if you want best sound quality. If you cut corners, then you push the tweeter beyond its limits.
This is exactly why most companies dont use just a single capacitor on a tweeter.